118 BULLETIN OF THE 



Key West, 2 to 5 fathoms. 



Tortugas, 5 to 6 " 



? Off the Samboes, 123 " 



This well-known species is found throughout the "West Indian seas, and 

 is very abundant on the reefs at and above low-water mark. I have 

 queried the depth 123 fathoms, fearing that some accidental transposition 

 of labels has taken place, as the Miihraculi are eminently littoral in their 

 habits, and the specimen so labelled is a full-grown male, similar in all 

 respects to those found on the shores. 



Mithraculus ruber nov. sp. 



Carapax subtriangular, one fifth broader than long; Surface naked, 

 polished, and uneven, but with the protuberances less numerous and 

 smaller than in M. sculptus and M. coronatus. These protuberances are 

 also rounded, and not elongated as in the allied species, and some of 

 them are sparsely tuberculated. Antero-lateral margin armed with three 

 teeth, besides the angle of the orbit, the posterior tooth being sharp, spini- 

 form, and curving forward, the other two teeth tuberculiform ; the middle 

 tooth is composed of two tubercles, and there is a small tubercle between 

 it and the posterior tooth. Behind the posterior tooth there is a small 

 sharp tubercle on the postero-lateral margin. The meros-joint of the outer 

 maxillipeds is slightly sinuous in front, showing a faint indication of a 

 notch. Chelipeda rather long and slender; meros armed above with six 

 small, conical, equal tubercles; carpus and hand smooth. Ambulatory 

 feel cylindrical, densely short hairy above (hairs simple) ; they are also 

 spinulose above, the spines being scattered in two rows. Color of the 

 carapax chestnut red. with some bluish posteriorly. 



Dimensions of a male : Length of the carapax, 0.48 ; breadth, 0.60 inch; 

 proportion, 1 : 1.25. 



It differs from M. scalptus, M. cinctimanus, and M. minutus in its broader 

 carapax, etc., and from M. coronatus in its spiniform lateral tooth and in 

 the character of the surface of the carapax. 



Found on the reef at Cruz del Padre, Cuba. 



Mithraculus coronatus Stm. 

 Cancer coronatus Herbst, Naturg. d. Krabben und Krebse, L 184; pi. xi, 



fig. 63 ('). 

 Mithraculus coronatus White, Brit. Mus. Cat. Crust., p. 7 (? partim). Stimp- 



son, Notes on N. American Crust., p. 58. Smith, Trans. Conn. Acad, of 



Arts and Sciences, II, 2. 

 It is somewhat doubtful whether this is really the Cancer coronatus of 



