214 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.24 



Megalobrachiumpoeyi (Guerin) 



Plate 16, fig. 4; plate 39, fig. 1 



Restricted synonymy: 



Porcellana poeyi Guerin, 1855, pi. 2, fig. 4 (type locality, Cuba). 

 Megalobrachium granulif erum Stimpson, 1858, p. 228 (listed only; 



type locality, Antilles); 1859, p. 76 (description; type localities 



restricted to Barbados and St. Thomas). 

 Megalobrachium poeyi, Benedict, 1901, p. 136, pi. 3, fig. 8. Boone, 



1931, p. 150, text-fig. 5. Haig, 1956a, p. 34. 



Previous Pacific records: 

 Costa Rica. Bahia de Salinas: Velero III (Haig). 

 Panama. Isla Taboguilla: W. G. Van Name (Boone). 



Diagnosis: Carapace roughly granular, posterolateral regions pli- 

 cate to rugose; lateral margins rounded; surface covered with long 

 plumose and non-plumose hairs; front with three shallow lobes; carpus 

 a little over one and a half times as long as wide, anterior margin 

 unarmed, surface with longitudinal crests; manus with longitudinal 

 crests, outer margin with a thick fringe of hairs ; telson with seven plates. 



Description: Carapace approximately as broad as long or slightly 

 broader, lateral margins rounded ; posterolateral regions plicate or some- 

 times rather strongly rugose, rest of surface with small rough granules; 

 entire surface covered with scattered long plumose and non-plumose 

 hairs, and frontal region with a short thick fringe of coarse clavate 

 hairs. Front projecting a little beyond eyes, trilobate or nearly trans- 

 verse in dorsal view; trilobate in frontal view, the lobes shallow, about 

 equal in length and breadth, lateral ones rounded, median triangular. 

 Eyes visible in dorsal view. Side walls and abdomen covered with long, 

 coarse, clavate hairs. 



Movable segments of antenna finely granular, without anterior pro- 

 jections, and bearing scattered, coarse clavate hairs; flagellum naked 

 or with vestigial hairs visible only under magnification. Outer maxilli- 

 peds punctate. 



Chelipeds covered with large, coarse granules. Merus with a low 

 ridge on anterior margin ; a few scattered, coarse clavate hairs on dorsal 

 surface and a thick fringe on posterior margin. Carpus a little over one 

 and a half times as long as wide, anterior margin unarmed; surface 

 with two broad, low, longitudinal crests and a third along posterior mar- 

 gin, these crests defined by narrow grooves; posterior margin with a 



