A New Platydesmoid Diplopod from 

 California 



By Ralph V. Chamberlin 



From Dr. Hilton I have received an adult and several imma- 

 ture specimens of the interesting new genus below described. 

 The male is not yet known. 



GosodesmiLs, gen. nov. 



A genus differing from Platydesmus and Brachycybe in its 

 much narrower keels, the body as a whole being slender, more as in 

 Dolistenus and Pseudodesmus, body differing from that of the last 

 mentioned genus in being much more depressed, the keels hori- 

 zontal or, on anterior segments, upturned. Keels for the most part 

 laterally a little thickened or margined. Dorsum of each segment 

 with two transverse rows of large tubercles which are laterally 

 compressed, in part cariniform, the median ones not greatly en- 

 larged as in Pseudodesmus, pores not pedicillate; opening at 

 margin. Fifth segment normal. Head as in Brachycybe : no eyes 

 present. 



Genotype. — G. claremontiis, sp. nov. 



Gosodesmus claremontus, sp. nov. 



The dorsum of the type is fulvus, in part of a distinct reddish 

 or pink tinge. The venter paler. 



Head shaped nearly as in Brachcybe lecontii but somewhat 

 narrower and the antennae a little more clavate. 



Keels of first five segments bent forwards, laterally strongly 

 rounded. Keels of sixth and seventh segments also bent forwards 

 but with the lateral margins straight at middle, the corners, how- 

 ever, widely rounded. On subsequent segments the keels have the 

 posterior corners extended a little caudad, the production becoming 

 pronounced in the caudal region. Keels of the penult segment pro- 

 duced directly caudad, nearly as far as caudal margin of last 

 tergite. Lateral margins of keels caudad of the eighth with 

 straight portion longer, slightly indented at middle, margined. 

 The angles on all keels remain rounded, but the posterior ones in 

 the more caudal segments narrowly so. Caudal margin of keels 

 toward mesal or proximal end bulging or shouldered, the caudally 

 extending portion abutting against or a little overlapping the 

 anterior border of the succeeding keel. First tergite with six 

 tubercles in each row, or with one or two extra ones in an indistinct 

 third row along anterior border. Tergites of middle region of 



