102 Bulletin, Vanderhilt Marine Museum, Vol. Ill 



Diagnostic characters: This is the large, common, edible, shell- 

 pinlv shrimp of the southern United States and tropic America. It 

 is readily distinguished from its associates by the presence on each 

 side of the rostral carina of a lateral sulcus, which extends the entire 

 length of the carapace. 



Distribution : Littoral. Abundant, usually in schools, in the waters 

 of the southern United States, occasionally swept northward in the 

 Gulf Stream as far as Massachusetts. Abundant throughout the West 

 Indian region as far south as Rio Grande du Sul, Brazil, Also found 

 on the West African coast from Senegal as far south as Angola. 

 Lefebrve indicates a fresh water habitat for the species at Lake 

 Aheme, Dahomey. So far as I am aware, the '^Ara" specimen is 

 the first record of the species from the Mediterranean Sea. 



Material examined : Two specimens taken on the South coast of 

 Cuba, field tag "G," February, 1925. One small specimen taken at 

 Guantanamo, Cuba, February 17, 1928. One specimen taken at 

 Turtle Harbor, Florida, January 10, 1923. One specimen dredged in 

 35 fathoms, 5 miles N. E. by N. of Cape Carthage, Gulf of Tunis, 

 Mediterranean Sea, July 21, 1927. One, Port Antonio, Jamaica, 2 

 fms., February, 1926. Three, West Indies. All collected by the 

 ^^Ara," William K. Vanderbilt, commanding. 



Technical description : Average size 4 to 6 inches long. Animal 

 rather robust, carapace not quite one-half as long as abdomen, exclu- 

 sive of telson ; rostrum prominent, slightly crested, extending beyond 

 the eye as far forward as the subdistal spine on the lateral margin of 

 the scaphocerite ; thickened; armed on the superior margin with 

 about eight teeth on the rostrum, and one more farther back on the 

 carapace; the inferior margin armed with two or three teeth; the 

 distal part of the rostrum directed straight forward. Posteriorly the 

 rostrum is continuous with a strong median longitudinal carina, 

 which extends to the posterior margin of the carapace, and is 

 bordered on each side by a sharp sulcus which is continuous anter- 

 iorly in a lessened degree onto the proximal part of the carapace. 

 There is a sharp antennal spine from which an oblique carina runs 

 back to the sulcus just in front of the sharp hepatic spine. Sub- 

 parallel to this carina is a wide deep sulcus which extends diagonally 

 upward almost to the orbital margin and has its upper lateral margin 

 defined by a carina. A small carina paralleled by a narrow groove 

 runs back from the upper side of the hepatic spine obliquely toward, 

 but not reaching the median line of the carapace. A similar, short, 



