308 M. Anton Stuxberg on Myriopoda 



known, viz. the Mexican one. The Craspedosoma deplanatum^ 

 n. sp., as bearing the strongest resemblance to a typical Poly- 

 desmuSj is unique, having no known ally in any part of 

 the earth. The Craspedosoma dahuricum, Gerstf., and the 

 C. cylindricum^ n. sp., may be regarded as representatives of 

 the European (J. Raivlinsii, Leach, their close resemblance in 

 form pointing to a near affinity of origin. The Polydesmus 

 clavatipeSy n. sp., is a form of the subgenus Icosidesmus, Humb. 

 & Saussure (distinguished by the strange conformation of the 

 legs), of which, as far as I know, only one species has been 

 described, viz. from New Zealand. If we except the Litho- 

 bius sibiricHSj Gerstf. (which has been, considering the claims 

 of the present time, very imperfectly described, and probably 

 is a collective species), and the L. osfiacormn, n. sp. (a Litho- 

 hius sensu strictiore*), the remaining Lithohii belong to that 

 division of the subgenus Archilithohius which is characterized 

 by four (never more) teeth on the coxal part of the second 

 pair of jaw-feet, and by usually 20-iointed antenna, and of 

 which the centre, to judge from the 119 species hitherto known 

 of the genus Lithohius in the wider sense, seems to be in the 

 north-east of Asia, though it has also some representatives in 

 Europe, and at least as many on the Californian coast. 



It is obvious from the foregoing remarks that the Siberian 

 Myriopoda have very little in common with those of Europe ; 

 and what there is leads us to suppose that Asia has been the 

 centre in which they originated. In order to acquire a true 

 knowledge of the geographical distribution of the species, it 

 makes a great difference whether we say that xisia has received 

 such and such forms from Europe, or that Europe has received 

 them from Asia. The Siberian Myriopod fauna is much too 

 independent, as it Avere, in its composition, to allow us to speak 

 of genuine European forms. It seems we shall come nearest 

 the truth by saying that Europe has borrowed from Asia the 

 Myriopods it has in common with Siberia. 



1. Lithohius ostiacoruni, n. sp. 



Lamina cephalica subcircularis, lateribus valde rotundatis, eadem 

 longitudine ac latitndiue, infra marginem posticum impressionibus 

 duabus rofiindate triangularibus evanidis, loevis, setis rigidis longis 

 sparse vestita ; anteunoe articulis 20, cylindraceis, louge setosis 

 eompositse, dimidiam corporis longitudinom assequentcs ; oculi 

 ellipsoidei, ocellis 9-10 in 3 series (l-f-3, 2, 3 v. l-|-3, 3, 3) 



* Compare Stuxberg, " Genera et Species Litliobioidarum " (CEfvers. 

 Kgl. Vet. Akad. n. s. Forliandl., arg. 32 (1875), no. 8), where (p. 8) the 

 six subgenera Eulithobius, NeoUthobins, Lithobius, Pseudoltthobtus, Hemi- 

 Hthobius, and Archilithobius are briefly characterized. 



