No. 1. The Henicopidae of America north of Mexico. 

 BY RALPH V. CHAMBERLIN. 



THE genus Henicops was proposed by Newport in 1844 for two 

 species, H. maculatus, from Van Diemen Land, and H. emarginattis, 

 from New Zealand. Twenty-four years later Meinert described from 

 Europe a species obviously related to these, placing it under a new 

 genus as Lamyctes fidvicornis; but by common consent subsequent 

 workers have, until recently, dropped Lamyctes as a synonym of 

 Henicops. However, in 1901, Pocock restudied Newport's species 

 and pointed out that maculatits, which he specified as the type of 

 Henicops, differed from the European species in having the tarsi of 

 the fourteenth and fifteenth pairs of legs, six segmented and those of 

 the anterior pairs trisegmented, the last three pairs of legs in fulvi- 

 cornis having the tarsi only bisegmented and the anterior legs having 

 the tarsi wholly undivided. In accordance with these important 

 differences Pocock again recognized Lamyctes as a distinct genus, 

 at the same time describing two new genera evidently closely allied, 

 Haasiella and Paralamyctes. 1 Other genera having more or less close 

 affinities with Henicops and Lamyctes have also been described by 

 Silvestri 2 and by the present writer. Silvestri and Pocock place these 

 genera, which, it may be noted, occur in the main in the Southern 

 Hemisphere, in a family Henicopidae in contrast particularly with 

 the Lithobiidae, including Lithobius and allies which abound for the 

 most part in the Northern Hemisphere; but Verhoeff in his recent 

 revision of the Lithobiomorpha in Die klassen und ordnungen des 

 thierreichs (1907, 5, p. 245f), does not recognize the family, denying 

 the sufficiency of the basis for it. Careful study of the genera of the 

 Lithobiomorpha, however, makes it very obvious that these (omitting 

 those of the Cermatobiidae) fall into two compact and clearly sepa- 

 rated groups and that, as one of these, the Henicopidae must be given 

 recognition as a distinct and well-defined family. 



1 R. I. Pocock, Some new genera and species of lithobiomorpkous chilopods. 

 Ann. mag. nat. hist., 1901, ser. 7, 7, p. 448-451. 



1 P. Silvestri, Descrizioni di alcuni generi e specie di Henicopidae. Boll. Lab. zool 

 R. scuola sup. agric. Portici, 1910, 4, p. 38-50. 



