92 CALIFORNIA ACADEMY OF SCIENCES. 



third; the dactyls in all the legs are little, if any, more than one-half the 

 length of the propodi and are curved at their corneous tips. Abdomen of 

 the male tapering evenly from the base to the tip; the sides of the penul- 

 timate joint are concave, those of the remaining joints straight. 



Length of carapace, 4.5 mm.; breadth, 9.5 mm.; length of third ambu- 

 latory leg, 11 mm. 



Bodega Bay! near Fort Bragg, California! 

 Pinnixa longipes (Lock.). 



Tuhicola longipes Lockington, Proc. Cal. Acad. Sci., Vol. VII, 1877, p. 55. 

 Pinnixa longipes Lockington, Ihid., Vol. VII, 1877, p. 156. Streets and 



JKiNGSLEY, Bull. Essex Inst., Vol. IX, 1877, p. 107. Holmes, Proc. 



Cal. Acad. Sci., 2d Ser., Vol. IV, 1895, p. 573, PI. XX, figs. 19 and 20. 



Carapace considerably more than twice as wide as long, somewhat flat- 

 tened above and furnished with a transverse depression behind the gastric 

 area. Front slightly projecting, furnished with a median groove and a 

 transverse groove behind the anterior margin. The last joint of the palp 

 of the maxillipeds is spatulate and joined near the base of, and slightly 

 exceeding the preceding joint. Chelipeds small, short, hairy; hands 

 oblong, compressed. First two pairs of ambulatory legs slender (the second 

 somewhat larger than the first), and furnished with slender, nearly straight 

 dactyls which are about equal in length to the propodi; following pair of 

 legs enormously developed; merus with a kind of flange on the posterior 

 margin; dactyl stout, curved, much shorter than the propodus; last pair 

 small and stout, scarcely reaching beyond the middle of the merus of the 

 preceding pair; dactyl stout, curved, shorter than the propodus. 



Tomales Bay (Lockington)! San Pedro, Calif. 



This species lives in the tube of an annelid worm 

 (Clymenella). It forms the extreme point of modifica- 

 tion of this peculiar genus. There is probably no other 

 crab which has such great width relatively to its length, 

 there is certainly no known species in which the fourth 

 pair of pereopods is so enormously enlarged; and I 

 believe there is no Brachyuran which exceeds it in 

 smallness of size. 



