636 Bulletin American Museum of Natural History {Vol. XLVIII 



fathoms; S. brk. Sh.; March 21; station D5678; 1 immature cf, the 

 chelipeds slightly developed, scarcely larger than the first ambulatory 

 leg. 



List of Larval Forms 



Dromidia larraburei 



Cape San Lucas, ship's anchorage, taken by electric light; one megalops, 5 mm. 



long. (See PI. XXXIII.. fig. 4.) 

 Point San Bartholome; one megalops, lacking chelipeds. 

 Middle of east side of Cerros Island, March 12, one female, early postlarval 



stage. 



As D. larraburei is the only dromiid in the region, the identification of the 



above is reasonably certain. 

 Carmen Island, southeast side, taken by electric light; one megalops, 2.9 mm. 



long. (See PL XXXIII, fig. 3.) This and the following forms are placed 



under Dromidia on account of the great development of the coxa of the 



hind legs. 

 Cape San Lucas; 5 megalopa, 3 mm. long. (See PI. XXXIII, figs. 1 and 2.) 



Callinectes 



Cape San Lucas; 50+ megalopa, 5 mm. long. (See PL XXXVI, fig. 3.) 



Cape San Lucas; 50+ megalopa, of two sizes. Seem to be the same as the 

 figured lot. 



Carmen Island, southeast side, taken by electric light; 50+ megalopa. Per- 

 haps same as the two preceding lots. 



San Francisquito Bay, taken by electric light; about 10 megalopa, with legs 

 broken off. Perhaps belong here. 



There are three species of Callinectes in the region; arcuatus, toxotes and 

 bellicosus. The first two were described from Cape San Lucas; bellicosus 

 is as near the Cape as La Paz on the one side and Magdalena Bay on the 

 other. According to Dr. Fish, the megalopa figured is almost identical 

 with that of Callinectes sapidus of the Atlantic coast. 



Portunidse, genus unknown, perhaps Callinectes 



Cape San Lucas; 3 megalopa, 6.6 mm. long. (See PL XXXVI, fig. 4.) 

 Pliosoma (?), or Libinia (?) 



Carmen Island, southeast side; one megalops, 2.2 mm. long. (See PL XXXVI, 

 fig. 2.) Dr. Fish says that this closely resembles an Atlantic species of 

 Libinia. 



Pachygrapsus crassipes (?) 



Cape San Lucas; one megalops. 



Guadalupe Island, taken by electric light, March 3; 25+ megalopa, 6 mm. long. 



(See PL XXXIV, figs. 1 and 2.) The large size indicates a large species of 



Grapsoid. 



Sesarma (Holometopus) magdalenense 



Carmen Island, southeast side, taken by electric light; one megalops. 



