232 CRABS OF THE FAMILY PERICERIDZ—RATHBUN. 
to Mr. James E. Benedict for valuable aid in the preparation of this 
paper. 
In the synonymy, quotations not verified are inclosed in parentheses. 
Numbers in parentheses after localities are taken from the catalogue 
books of the museum. 
The drawings were made by Mr. A. H, Baldwin, excepting those of 
Libinia emarginata and dubia, which are republished from “The Fish- 
eries and Fishery Industries of the United States,” through the cour- 
tesy of the U. S. Fish Commissioner. 
Tn an appendix are given descriptions of Pericerid:e collected by the 
North Pacific Exploring Expedition, preliminary notices of which were 
published by Dr. William Stimpson, in the Proceedings of the Phila- 
delphia Academy of Natural Sciences, 1857. The specimens were 
destroyed in the Chicago fire. The figures have been copied and en- 
larged by Mr. Baldwin from the drawings accompanying the original 
manuscript. 
PERICERIDA. 
Maioid brachyurans with eyes retractile in complete and well-defined 
orbits. Basal antennal joint well developed and forming the greater 
portion of the inferior wall of the orbit. 
KEY TO SUBFAMILIES. 
antenne not dilated. Fingers acute at tips..................... Pericerine. 
A” Carapace suboblong; interorbital space very broad. Rostrum verysmall. Sec- 
ond joint of antennz enlarged. Fingers excavated at tips... .... Othoniine. 
KEY TO GENERA, 
Pericerine. 
A’ Rostrum not divided to the base. 
Bb brsotular spine distines. ss... 452. 52.246..< och. ee ee Libinia. 
Bi Ereooular spine absent..0--. 2.008 be ee eee Prionorhynchus. 
A’ Rostrum composed of two distinct spines. 
B’ Basal joint of antennxz without spine at distal extremity. 
"(Horns of ‘rostrum| lamellate) 27/278 2 9 ee Pyria,* 
C” Horns of rostrum flattened, contiguous, produced at their extremities in a 
lateral lobe... os. eeece see ee ee a's fats crnrat pee ete Ae nS Lissa. 
C’” Horns of rostrum slender and GivGrpent soe oar soe ee ee Picroceroides. 
C”” (Horns of rostrum very slender and conti PUOUS) 25 Eeeee cee Leptopisa. 
C’’”" (Horns of rostrum small, parallel to each other)............._... Sisyphus.* 
D’ (Nearly vertically deflexed in front of gastric region)....... Cyphocarcinus. 
D” (Not deflexed in front of gastric Fesion) 7-2 oek. PE ene Podohuenia. 
“May belong to the Maiid=. 
