Pomona College Journal of Entomology 477 



BB. Claw of anal legs witii distinct basal spines; cephalic plate distinctly 

 and considerably overlapping tile first dorsal plate. 



Genus Scolopendra Linnaeus. 



Genus Hemiscolopendra Kraepelin 

 This genus is peculiar to the western hemisphere. Its species have for the 

 most part been considered under Scolopendra, which they conform to in general 

 habit and structure. One species (//. punctiventris Newport) is widespread in 

 the eastern United States, but none is known from California. 



Genus Arthrorhabdinus Verhoeff 

 Established as a subgenus to Arthrorhabdus, a South African genus, for the 

 Texan species A. pygmaeus Pocock, a species which may possibly range across 

 Arizona into southern California and which is accordingly included here. 



Genus Scolopendra Linnaeus 



This, the typical centipede genus, embraces about two dozen valid species 

 and presents an excessive range under these of minor geographical forms, of 

 which a very large number have by different authors been dignified as species. 

 The variability in size, color, and many other characters is extreme. It is cosmo- 

 politan in the warmer zones of the earth. 



No basal plate present. Antennae composed of seventeen to thirty-one arti- 

 cles, of which the proximal four or more are glabrous. Prosternum with dental 

 plate ; femur of prehensorial feet with basal tooth. Pseudopleura with toothed 

 or spined caudal process. A tarsal spine on each leg excepting last pair. Pre- 

 femur of anal legs spined, always with spines at apical process or angle. 



The species occurring within California may be distinguished as follows: 



Key to Species of Scolopendra 



A. First dorsal plate with a deep transverse impression back of anterior mar- 

 gin. 



B. Cephalic plate impressed with two fine longitudinal furrows which di- 

 verge cephalad; length 100 to 200 mm. S. heros Girard. 

 BB. Ce])halic plate wholly without furrows or at most with a weak median 

 furrow; first legs with two tarsal spines; length mostly from 50 to 

 100 mm. 

 C. Apical process of prefemur of anal legs mostly with four spines; ce- 

 phalic plate always without any furrows. S. polymorpha Wood. 

 AA. First dorsal plate without a deep transverse impression back of cephalic 

 margin (legs of first pair with but one tarsal spine). 

 B. Prefemur of anal legs with none to five spines only. 

 C. Prefemur of anal legs without spines beneath and at most with two on 

 the inner or mesal surface. S. dehaani Brandt. 

 CC. Prefemur of anal legs with four or five spines, of which two are always 

 ventral in position. S. subspinipes Leach. 

 BB. Prefemur of anal legs with ten to fifteen spines, of which six to nine 

 are ventral in position and arranged in three series. 

 C. Apical process of prefemur bearing three or four spines. , 



S. morsitans Linnaeus. 



