520 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. XXI. 



granules; meri broad, with very convex upper margins; dactyli very 

 long, considerably exceeding the propodal joints. 



Dimensions. — Female: Length, 24.5 mm. ; width, 35.6 mm. ; exorbital 

 width, 23.5 mm.; width of front above, 10.5 mm.; depth of front, 1 m. 



Type. — No. 41)15, Mus. Comp. Zool.; one female. Para, Brazil; Agas- 

 siz and Bourget, Thayer expedition. 



PSEUDOTHELPHUSA FOSSOR, new species. 



Boscia dentata Gerst.eckek, Arch. f. Naturg., 1856, XXII, Pt. 1, p. 145. 

 dentata Milne-Edwards. 



Not Boscia 



Superior margin of front tuberculate, not heeled, hilohate; surf aee finely 

 granulate ; cervical suture straight ; merus of maxillipeds with outer mar- 

 gin convex } exognath reduced to a stump. 



Carapace about three-fifths as long as wide, 

 convex in both directions, smooth to the eye, 

 finely punctate, faintly granulate along the frontal 

 and lateral margins. Cervical suture very shal- 

 low, straight, scarcely distinguishable near the 

 margin of the carapace. There is a sliallow de- 

 pression behind the outer end of the cervical 

 suture. Median suture sufficiently marked; epi- 

 gastric lobes narrow, distinct. Lateral margins 

 denticulate; a shallow tooth is present at one- 

 third the distance from the orbit to the (;ervical 

 suture. The frontal region in advance of the epi- 

 gastric lobes is deflexed. The front itself is per- 

 pendicular, about one-fourth the width of the 

 carapace, shallow, deepest near the outer ends 

 (fig. 11, a); lower bonier marginate, sinuous; up- 

 per border tuberculate, straight when viewed 

 from above, inclining slightly toward the middle 

 when viewed from in front. The orbits belong to the group having a 

 more or less quadrate outline; upi)er margin nearly transverse, lower 

 margin running downward and outward from the inner angle. The 

 eyes are rather large. The maxillipeds (fig. 11, h) have the outer 

 margin of the merus and ischium of the endoguath regularly convex, 

 the ischium having its greatest width at some distance back of the 

 distal end. The merus is not much wider than long. The exognath 

 is much reduced, not reaching more than one-third the length of the 

 margin of the ischium. 



Chelipeds very unequal, covered with scabrous granules. Carpal 

 tooth acute. Palm (fig. 11, c) with convex margins; fingers wide, meet- 

 ing along their cutting edges, tips crossing, teeth white. Ambulatory 

 legs with meral joints dilated in the middle; otherwise long and nar- 

 row. Dactyli long and slender, armed with very slender spines. 



Dimensions. — Female: Length, 17.6 mm. ; width, 28.7 mm.; width of 

 front on lower margin, 6.5 mm; greatest depth of front, 1 m. 



Fig. 11.— Pskudothelphusa 



P0S80K. a. FEONT, NAT- 

 UEAL SIZE. &. MaXIL- 



LiPED, x2J. c. Larger 



CHELA, FEMALE, NATURAL 



SIZE. d. Left abdomi- 

 nal APPENDAGE, MALE, 



LOWER VIEW, X 5. e. The 



same; INNER VIEW, X 5. 



