Chilopoda 19 H 



coxae of the second maxillae is narrower and apparently more membranous in 

 alaskanus and the anterior margin presents a distinctly reentrant angle at the 

 middle instead of being straight. The cephalic plate is broader anteriorly, 

 the caudal angles more rounded, the anterior margin protruding forward between 

 antennae instead of being excavated or reentrant, and the hairs are fewer and 

 finer. The exposed area of the basal plate is proportionately longer. There 

 is the likelihood that the specimens secured by the Vega at Port Clarence belong 

 to the present species rather than to the true glacialis as fixed by description 

 and figures. 



LlTHOBIOMORPHA. 



Of this order one family is represented in the collection made by the Cana- 

 dian Expedition. Another family is also known to occur in the Alaskan fauna, 

 the Ethopolidae, in which a new subspecies of Ethopolys from Sitka is described 

 below. It is very probable that members of the.Henicopidse will also be found 

 in the region; for, though this family on the whole is particularly characteristic 

 of the southern hemisphere, Lamyctes is not uncommon in north temperate 

 latitudes and the Zygethobiine group is characteristically North American. 

 This group embraces largely mountain-loving forms; and Zygethobius is already 

 known to occur in the high mountains of British Columbia which should naturally 

 carry its range into the present territory. 



LITHOBIID^E. 



In addition to the species separately listed below, another species has been 

 recorded from Port Clarence, which is very close to the locality from which the 

 specimens of E. stejnegeri were secured by the Expedition. This is Monotar- 

 sobius tricalcaratus Attems. In the southern part of Alaska, namely from 

 Forrester island, are also found Oabius uleorus Chamberlin and Paobius boreus 

 Chamberlin. 



Ezembius Chamberlin. 



This genus was established for a group of subarctic species of which the one 

 here listed is the genotype. The following Siberian species, among others, 

 belong in the genus: Ostiacorum, princeps, sulcipes, and scrobiculatus Stuxberg. 



Ezembius stejnegeri (Bollman). 



1893. Lithobius stejnegeri Bollman, Bull. U.S. Nat. Mus., 46, p. 149 

 Lithobius sulcipes Bollman, loc. cit., p. 199. 



1909. Monotarsobius arcticus Attems, Arkiv for Zool., 5, No. 3, p. 19. 

 Lithobius (Archilithobius) haasei Attems, loc. cit., p. 22. 



Of this species Mr. Johansen secured three females at Teller, Alaska, on 

 July 31, 1913, his note stating that they were found " under old sacks, tins, 

 etc., on tundra behind town." 



The species is widespread in this general region, and appears to abound 

 particularly on Pribilof and other islands. After a study of considerable material, 

 I am unable to detect more than one species and conclude that the sulcipes of 

 Bollman, and certainly the Monotarsobius arcticus and Lithobius (Archilithobius) 

 haasei of Attems, all described from Bering island, are one and the same as E. 

 stejnegeri, which in turn, may prove to be identical with sulcipes Stuxberg 

 (1875), if not, indeed, with the much earlier L. sibiricus of Gerstfeldt (1858). 



ETHOPOLID^). 



Occasion is taken to describe here a new Alaskan form of Ethopolys. As 

 this is regarded as a subspecies of a new species occurring in Washington and 

 Oregon, a description of the latter is also introduced. 



