Geophilus is a large, heterogeneous genus of soil centipedes in the family Geophilidae largely considered to be synonymous with Brachygeophilus. It is a mostly holarctic genus characterized by a claw-shaped ultimate pretarsus, anterior porefields, complete or nearly complete coxo-pleural sutures at the prosternum, and incomplete chitin-lines. Centipedes in this genus range from 1 cm to 8 cm in length. The generic name first appeared in Brewster's Edinburgh Encyclopaedia in 1814 as Geophilus electricus.
Linotaeniidae are a monophyletic clade of soil centipedes in the family Geophilidae found mostly in the temperate regions of the Holarctic as well as the south Andes. Species in the clade Linotaeniidae are characterized by a body that usually tapers toward the anterior tip; mandibles with a single pectinate lamella; second maxillae with coxo-sternite usually undivided and claws without projections; forcipular segment short, with tergite remarkably wide, forcipules evidently tapering; coxal organs opening through distinct pores on the ventral surface of the coxo-pleura. The number of legs in this clade varies within as well as among species and ranges from as few as 31 pairs of legs to as many as 83 leg pairs. Compared to most families in the suborder Adesmata, this clade features a modest number of leg-bearing segments and limited variation in this number within each species.
Geophilus electricus is a species of soil centipede in the family Geophilidae found across temperate Europe, especially Britain and Ireland. Originally discovered and named Scolopendra electrica in 1758, it was later moved to its own genus, Geophilus. As the first species described in this genus, it is considered by some to be the type species. It is yellowish-orange in color and can grow up to 45 millimeters, with 55 to 75 leg pairs, a distinct carpophagus fossae on the anterior sternites, and a distinctive arrangement of the coxal pores of the last leg pair. Like many geophilomorphans, G. electricus has been known to glow in the dark, most likely as a defensive maneuver.
Geophilus proximus is a species of soil centipede in the family Geophilidae found in the northern part of the Palearctic and widespread across the entire Baltic basin, though it reaches as far as the Arctic Circle and has been introduced through human agency to northern, central, and eastern parts of Kazakhstan. It was recorded once with certainty in Britain from Unst in the Shetland Islands; distribution in the rest of Europe is difficult to assess because of frequent misidentifications of the species. Populations from northern Europe are mostly parthenogenetic.
Geophilus admarinus is a species of soil centipede in the family Geophilidae. It's found in southeast Alaska under stones near the low tide mark and is capable of surviving prolonged submersion underwater.
Geophilus impressus is a species of soil centipede in the family Geophilidae found all over Europe, and has also been recorded in North Africa. It lives frequently in endogean habitats; in Sardinia it's found mostly in Quercus ilex woods, but also in Mediterranean shrub, open habitats, and maquis. It lives anywhere from sea level to 1700 meters above it, sometimes in caves.
Geophilus alaskanus is a species of soil centipede in the family Geophilidae found in Alaska. It bears similarities to Mecistocephalus attenuatus, however unlike M. attenuatus, it has oblong cephalic lamina, unarmed coxae, and unarmed claw at base. G. alaskanus is dull orange-brown in color, grows to about 30 millimeters, and has 53 leg pairs with the first pair being very small and the last pair being distinctly larger than the others. It also possesses coalesced frontal lamina, unexposed basal lamina broader than the cephalic, a prehensorial sternum that's broader than it is long, distinct lateral grooves, obsolete prosternal teeth, a smooth, bare dorsal surface except for two faint impressed lines, and a small pleurae of the last segment marked with 8–10 pigmented pores of which the posterior one of the ventral face is larger than the others and sunk in a deep cavity.
Geophilus algarum is a species of centipede in the family Geophilidae found in the littoral zone on the French Atlantic and Channel Coasts. It has one subspecies, G. algarum var. decipiens, which can be identified by lack of a dorsal coxal pore. The male of this species has 53 pairs of legs; females have 53 to 59.
Geophilus mordax, also called the pitted soil centipede, is a species of soil centipede in the family Geophilidae found in North America, especially Indiana, Arkansas, Louisiana, North and South Carolina, and Florida. It grows up to 50 millimeters in length, though it averages 25–40, has 49–53 leg pairs in males and 49–57 in females, and is bright red in color. G. mordax also bears 3–5 labral teeth, a short and robust apical claw of the second maxillae, an exposed prebasal plate, and a large, consolidated sacculi.
Geophilus alzonis is a species of soil centipede in the family Geophilidae found in Monte Alzo near Tolosa in Spain, which it was named after. It's a poorly defined species that was described as being light yellow with a light chestnut brown head and 13–14 mm long, with small but numerous leg bristles, sternites bearing three longitudinal furrows, a carpophagus formation from segments 3–6 to segments 11th-13, and 37-51 leg pairs.
Geophilus nanus is a species of soil centipede in the family Geophilidae found on the Iberian Peninsula. It's a poorly defined species described as being pale yellow, 15 mm long, with smooth sternites bearing no furrows, final hip with few pores next to the sternite rim, tergites deeply double-furrowed from the basal shield onward, and 41 leg pairs. It’s apparently related to G. gracilis, differentiated by jaws that do not surpass the forehead or bear chitin lines, and by the 2nd tarsal segment of the final leg pair being just a tiny stub.
Geophilus anonyx is a species of soil centipede in the family Geophilidae found in Oregon. It was originally placed in the genus Brachygeophilus based on the lack of sternal pores, a character shared with the type species B. truncorum, however it was later moved to Geophilus.
Geophilus atopodon is a species of soil centipede in the family Geophilidae found in Beulah, New Mexico. Its body is uniformly light brown, up to 25 millimeters long and rather thick, narrowed posteriorly, with 49–51 leg pairs, a discrete frontal plate, and a long claw of the anal legs.
Geophilus becki is a species of soil centipede in the family Geophilidae found in Cabrillo Beach, California near San Pedro under rocks and kelp at the water's edge. It grows up to 50 millimeters long and is generally orange-yellow in color with clear yellow legs and 61-63 leg pairs.
Geophilus glaber is a species of soil centipede in the family Geophilidae found beneath logs and other debris in California. It grows up to 53 millimeters long, with a discrete frontal plate, large anal pores, and slender feet of the last legs. The female of this species has 53 or 55 pairs of legs.
Diphyonyx conjungens, formerly Geophilus conjungens, is a species of soil centipede in the family Geophilidae that has been recorded in the Balkan Peninsula, Anatolia, the southern Sporades islands, the most eastern parts of Turkish Armenia, the Pontic and Tauric mountains, and Crimea. It grows up to 60 millimeters long and bears 69–81 leg pairs, as well as 1–2 stout tubercles and 2–4 slender filaments on the mid-part of the labrum, an absence of condyles between the anterior trunk sterna, and a single, isolated pore on each coxo-pleuron.
Geophilus nicolanus is a species of soil centipede in the family Geophilidae found on San Nicholas Island, California. It's dark brown in color and grows up to 62 millimeters long, with 63 leg pairs, a concealed prebasal plate, numerous coxal pores, and a very wide final ventral plate with convex sides.
Geophilus tampophor is a species of soil centipede in the family Geophilidae found in Oregon. It was originally placed in the genus Brachygeophilus, however it was later moved to Geophilus. Like G. anonyx, it differs from other western American geophiliids by having prehensorial claws armed at the base, however unlike G. anonyx it possesses armed anal claws and a lesser number of legs.
Geophilus truncorum is a species of soil centipede in the family Geophilidae found across Western Europe, though it reaches as far as Poland, Italy, and Morocco. This centipede is relatively small, growing up to 20mm in length, with a yellow or orangeish brown body and dark yellow or brown head, denser and shorter hair than most Geophilus species, a main plate almost as elongated as in G. flavus (115:100), and distinct carpophagus fossae on the anterior sternites. Males of this species have 35 to 41 pairs of legs; females have 37 to 41.
Geophilus erzurumensis is a species of soil centipede in the family Geophilidae found only in Erzurum, Turkey, which it is named after.
