54 COOK 



pods separate it from X. dissecta, and probably also from X.furci- 

 fer. 



XYSTOCHEIR ACUTA sp. nov. 



Type collected in California by Mr. Carl F. Baker. 



Length of male about 35 mm., width 6.5 mm. 



Color in alcohol fading to fawn-color ; dorsum lighter, legs and an- 

 tennae darker. 



Segments with posterior corners of carinaa strongly produced, and 

 the projecting corner thickened to increase the size of the poriferous 

 callus. Segment 19 exceeding segment 18, but the pores very minute, 

 as in X. obtusa. 



Gonapods with second joint oblong, scarcely tapering to near the 

 end ; lateral spine flattened, inserted somewhat above the level of the 

 anterior, its apex scarcely exceeded by the distal spines. Posterior 

 distal spine thin and leaf-like, the apex broadly rounded. Anterior 

 spine relatively smaller than in X. obtusa. 



This species differs from the preceding in its larger size and some- 

 what more convex dorsum, and in minor details of the gonapods, as 

 described above, but the principal diagnostic feature seems to lie in the 

 longer and much more produced lateral carinae. 



Several adult specimens of both sexes were received from Mr. Carl 

 F. Baker, and are supposed to have been collected near Palo Alto, 

 California. Another pair was obtained by Prof. Walter C. Blasdale 

 in June, 1891, at Berkeley. 



XYSTOCHEIR FURCIFER (Karsch). 



Polydesmus (Fontarid) furcifer KARSCH, Troschel's Archiv f. Naturgesch., 



XLVII, p. 39, pi. 3, fig. 12, 1 88 1. 

 Fontaria furcifer BOLLMAN, Bull. 46, U. S. Nat. Mus., p. 123, 1893. 



Type in the Berlin Museum, collected by Forrer. 



It is not impossible that this species may prove to be a synonym of X. 

 dissecta (Wood) , for although the description says that the gonapods 

 are trifurcate at the base, the figure shows two principal divisions, as 

 claimed by Wood, with a short, broad process from near the base of 

 the posterior, instead of the slender spine of the two preceding species. 

 Karsch's figure also represents the anterior of the two principal di- 

 visions as about twice as long as the process next above it, instead of 

 about half as long as in X. obtusa and X. acuta. 



