P E N JE I D E A. 605 



PEN^EUS MONOCEROS, Fabr. 

 Plate 40, fig. 5, outline of carapax, natural size. 

 Singapore ? 



Length of body, three and one-eighth inches; of abdomen, two 

 inches. 



Penseus monoceros, FABRicius, Suppl., 409 ; EDWARDS, Crust., ii. 415. 



TENUIS. 



Rostrum supra multidentatum (dentibus novem vel pluribus), parce 

 sinuosum. Carapax dorso postice non carinatus nee sulcatus. Oculi 

 sat longi. Flagella antennarum internarum subcequa, carapace vix 

 breviora. 



Beak slightly sinuous, above multidentate (teeth nine or more in 

 number). Carapax not carinate nor sulcate on posterior half of 

 back. Eyes rather long. Flagella of inner antennae subequal, 

 hardly shorter than carapax. 



Plate 40, fig. 6, outline of carapax and inner antennae, twice the 

 natural size. 



Off Rio Negro, Northern Patagonia, in the Atlantic. Taken from 

 the stomach of a fish. 



Length, one and one-half inches. The specimens are all mutilated. 

 The beak is broken, and we cannot give the character of the under 

 margin or extremity beyond what is represented in the figure. The 

 fifth and sixth abdominal segments are carinate above ; the last is 

 without lateral spines. Fifth pair of legs but little more slender than 

 the preceding pair. 



152 



