568 Monograph of the 



tacea, a study which was abruptly broken off at the com- 

 mencement of the present war. This will account for any 

 want of completeness which may appear in the article, 

 and for the absence of figures, which were necessarily left 

 unfinished. The high degree of interest attaching to the 

 discovery of such remarkable differences in the append- 

 ages to the male abdomen of forms supposed to be the 

 same by all previous carcinological writers, may serve as 

 an excuse for presenting the paper in its present incom- 

 plete form, against the original intentions of its author. — 

 William Stimpson.] 



CALLINECTES HASTATUS Ordway. 



Lupa hastata Say, Jour. Acad. Nat, Sci. Philad., i. 65. 



Carapax in adult specimens about twice as broad as 

 long ; anterior portion sparsely granulated, cardiac and 

 branchial regions more finely and densely so ; areolations 

 quite distinctly marked, but not so strongly as in diacanthus. 

 Teeth of the antero-lateral border conical and pointed, with 

 the sides concave in adult specimens ; posterior tooth more 

 than twice as long as the others. Anterior edge of the 

 carapax, that is, the orbit of the eye and the front, finely 

 beaded. Front with two broad, inequilateral, triangular 

 teeth, there being no median teeth present. Sub-median 

 tooth of front rather broad and conical, and well developed. 

 Lower margin of the orbit strongly beaded, in adult indi- 

 viduals with a slight spinous armature at its interior angle. 

 Pterygostomian region densely pubescent in its posterior 

 portion, but towards its anterior portion almost naked; 

 — perhaps the hair is here worn away by the action of the 

 chclipeds. Abdomen of male rather broad; last segment 

 broad and triangular ; penultimate segment constricted 

 near the base, with a concave lateral outline. The intro- 

 mittent organs are very long, reaching almost, or quite, to 

 the extremity of the abdomen. They have two curves, 



