DECAPOD CRUSTACEANS OF THE WEST INDIES 187 



Dominica Stations: 1, 2, 4, 6, 11, 13-18, 24, 30, 33, 36-38, 42, 

 54-56, 59, 61-64, 68, 83, 88, 95, 100, 102, 126-128 (0-400 ft. — one 

 record of 2,500 ft.). 



Remarks. — Comparsion of the first pleopods from a male syntype 

 of S. roberti with those from the male used by Rathbim (1918) to 

 illustrate S. angustipes leaves no doubt that the specimens assigned 

 by her to these two species are conspecific, as suggested by Hartnoll 

 (1965, p. 133). We are not convinced, however, that S. roberti is a 

 junior synonym of S. angustipes Dana, 1852, from "South America." 

 Dana noted that his species has the "frontal margin very slightly 

 excavate at middle," and his figure indicates a median sinus that is 

 far less pronoimced than the frontal indentation in S. roberti. Until 

 specimens with the distinctive pleopodal and frontal characters of the 

 Caribbean species are found on the northeastern and eastern coast 

 of South America (Dana's material presumably came from near Rio 

 de Janeiro), it seems best to consider the two species distinct. Un- 

 fortunately, Rathbun (1897) did not indicate why she doubted that 

 the specimens from Montevideo tentatively determined by Miers 

 (1881a) as S. angustipes belonged to Dana's species and therefore 

 required a new name, S. miersii. It seems to us that the widely rang- 

 ing S. miersii fits Dana's description at least as well as does S. roberti. 



Ovigerous specimens were taken on Dominica in all months in 

 which females were collected: January, February, March, and De- 

 cember. The megalops stages and probable first instar were collected 

 on March 5. 



74. Sesarma (Sesarma) bidentatum Benedict 



Figure 62o 



Sesarma bidentata Benedict, 1892, p. 77 [type-locality: Jamaica]. 

 Sesarma (Sesarma) bidentata. — Rathbun, 1897a, p. 89. 

 Sesarma (Sesarma) bidentatum. — Rathbun, 1918, p. 295, pi. 80. 

 Sesarma bidentatum. — Hartnoll, 1964, p. 159, figs. 12a-c, 13, 14a. 



Diagnosis. — Carapace subrectangular, between four-fifths and 

 nine-tenths as long in midline as wide, somewhat convex near lateral 

 margins, more or less flattened on posterior gastric region and on 

 cardiac region, obscurely striate laterally, rather smooth and irregu- 

 larly punctate elsewhere; lateral margins converging anteriorly, with 

 low blunt tooth posterior to outer orbital angle, fronto-orbital dis- 

 tance slightly more than four-fifths of maximum width of carapace; 

 front abruptly deflexed at postfrontal lobes, less than half as wide as 

 carapace, margin with pronounced broad median sinus in dorsal view. 

 Eyes well developed, cornea slightly narrower than eyestalk. True 

 ventral margin of orbit largely replaced by hairy granulate nearly 

 straight ridge accentuated posteriorly by distinct groove, mesial end 



317-180—69 14 



