AA Ras we Rag eae ee 
258 CRABS OF THE FAMILY PERICERIDHZ—RATHBUN. 
posterior end of the mesogastric, one on the anterior edge of the car- 
diac. There is a long line of stout granules a little above the posterior 
margin; a Shorter line of granules behind this; a curved line of four 
granules just back of the middle of the cardiac region, arranged con- 
cave to the posterior margin; and two lines of granules on the posterior 
half of the branchial region, one following the general direction of the 
4 
posterior margin, the other shorter, along the inner boundary of the 
branchial region and meeting the first line at an acute angle. There 
- 
are other granules scattered on the carapace, but no conspicuous pro- _ 
tuberances on the hepatic region. 
Lobes of the rostrum acute, emarginate on their inner margins near 
the tips. Orbital angles sharp, the inner one produced in a line with 
the tip of the rostrum, the outer angle less produced. 
Antero-lateral teeth five, irregular, the second small and somewhat 
coalesced with the third at its base. Carapace broadest at the fourth 
tooth. Fifth tooth small. 
Basal joint of antenna with its anterior margin cut into three irregu- 
lar teeth. Second joint with the lobe at its outer angle projecting — 
} 
laterally, but not so long as im aculeata. 
Meral joint of outer maxillipeds longer than broad; antero- external 
angle produced; no perceptible notch at internal angle, 
Yhelipeds in the young female slender, no longer than the first pair 
of ambulatory legs. Merus somewhat angled; carpus compressed; 
upper and lower margins of hand subparallel; fingers finely dentate, 
with a narrow hiatus at their base. 
Ambulatory legs with a fine scattered pubescence. Carpal joints dis-_ 
tended as in aculeata with an uneven ridge above and a longitudinal 
depression on the outer face. 
Length from tip of rostrum, 9 millimeters; greatest width, 8.5 mil-— 
limeters. 
Collected in the Gulf of California, lat. 29° 30’ N., long. 112° 40’ W., 
45 fath., by Lieut. Commander H. E. Nichols, U. S. Navy, 1880-1882 
(15822); specimen imperfect, dried. 
This species can hardly be identical with O. picteti Saussure (Rev. et — ! 
Mag. de Zool. (2), V, p. 357, pl. 13, fig. 2, 1853) as the carapace is broader 
posteriorly, the tubercles are differently disposed, the front is broader, 
and the orbital angles more produced than in Saussure’s figure. 
Othonia rotunda, sp. noy. 
Plate xxxVIl, fig. 1. 
Carapace as broad as long, widest at the fourth antero-lateral teeth, | 
much swollen in both directions, transversely rising abruptly from the | 
bases of the antero-lateral teeth, longitudinally rising in almost an — 
equal curve from behind the front and from the posterior margin. Re- 
gions faintly indicated. Carapace covered with granules which are 
more thickly set on the posterior half, Long fine hairs proceed from 
