LIFE HISTORY OF THE BLUE CRAB. 399 
c. Movable portion of the antenna excluded from the orbital cavity by a pro- 
longation of the basal joint of the antenna .........-..-. Charybdella. 
c!. Movable portion of the antenna not excluded from the orbit. 
d;-No longitudinal ridge on the palate. -.:..:-..20..2-055.-..2222--2 Areneus. 
d', A longitudinal ridge on the palate. 
e; Abdomen of the male j-shaped -..../...0.0.d¢2.i.5-2eee-2en Callinectes. 
a. Apmomer of the male triangular. .\. 6229298. sos ee kc bce Portunus. 
i’. Carapace not very broad, antero-lateral margins cut into five teeth. 
c. Last tooth of antero-lateral margin developed into a spine longer than the 
Otber teethror sprmest 1. ssn ae eee sae inact en eae Bathynectes. 
all -antero-lateral: teeth similar 22 S504 ye ee Pee tek... Ovalipes. 
«, Last pair of legs narrow, with terminal segment lanceolate_.......... Carcinides. 
Of the nine species of the genus Callinectes five have been recorded 
from the United States. They are C. sapidus Rathbun, C. ernatus 
Ordway, C. danz Smith, C. larvatus Ordway, and C. exasperatus Ordway. 
Of these the first is distributed along the Atlantic coast from Massa- 
chusetts Bay to Florida and along the coast of the Gulf of Mexico, 
the Caribbean Sea, and the Atlantic coast of South America as far 
south as Brazil; C. ornatus Ordway has been found as far north as 
Charleston, 5. C., and thence southward to Victoria, Brazil; C. dane 
Smith has been collected at various localities between South Carolina 
and Santos, Brazil¢; C. darvatus Ordway has been reported from some 
of the Florida keys, from Vera Cruz, Mexico, from various islands of 
the Bahamas and the West Indies, from the coast of Brazil, and from 
the West coast of Africa; C. exasperatus Ordway has been collected at 
Key West., Fla., Jamaica, Old Providence, and at several points on 
the coast of Brazil. In addition to these, C. bocourti Milne-Edwards 
occurs on the coasts of Central and South America; C. ereuatus Ord- 
way is found in the Gulf of California and Pacific coasts of Mexico 
and Central America; C. toxotes Ordway from Cape St. Lucas to Guaya- 
quil, Ecuador; C. del/icosus (Stimpson) from numerous points in Lower 
California and in the Gulf of California; and (@. nitidus A. Milne 
Edwards from Guatemala probably to Chile. 
Some of the species are very distinct, but others are distinguished 
with difficulty. The following key, revised from Miss Rathbun’s, will 
serve for their identification. 
a. Inner supraorbital fissure closed. 
ip, brome with tounmamraorpital teeth cc. 2. ines A a2 58k ee C. sapidus. 
b', Front with six intraorbital teeth. 
c. Verges much shorter than the abdomen. 
; d. Lateral spine more than twice the length of preceding tooth. 
e. Intramedial region broad, its anterior width about three times its 
I Retayesi il cWesaepee tes > Be “ge ee ilen Ae COE Oe ee C. ornatus. 
@ The occurrence of C. sapidus in a fresh water basin at Rochefort, France, recorded 
by Bouvier (Bulletin Musee Paris, VII, 16), is, as that author suggests, to be regarded 
as entirely accidental, the specimen having been carried across the Atlantic in some 
vessel. 
