92 BafJtbun — Synopsis of fJie American Sesarmas. 



greater than tlie anterior; the widtli (if the ambulatory legs is also vari- 

 able, but as a rule the nieri are shorter than in S. robeiil. 



UlMrllmtlon. — -Abaco and 8an Salvador, Bahamas; Swan Island, Carib- 

 bean Sea (U. S. Nat. Mus. )• Destero, Brazil (Paris Mus.). Rio de Janeiro ; 

 Rat Island, Monte Video, type locality (Brit. Mus.) 



Sesarma (Holometopiis) hanseni Rathl)un, new species. 



Carapace much broader than long, broader anteriorly than posterioi'ly. 

 Regions well marked ; mesogastric verj' wide behind, and with a curved 

 sulcus parallel to its posterior margin. Surface smooth and punctate and 

 without granulations. Superior margin of front uneven, the inner lobes 

 sloping backward from the middle. Front more than 4 times as wide as 

 high ; margin ])rojecting, thin, arcuate in a front view, slightly sinuous in 

 a dorsal view. Terminalsegment of abdomen broader than long. Appen- 

 dages narrow and with slender curved tips. 



Merus and carpus of chelipeds with outer surface covered with broken 

 rugose lines ; margins denticulate. Hand deep, covered with depressed 

 tubercles ; superior margin with a thin denticulate crest. Fingers irregu- 

 larly toothed; the largest tooth of the dactylus is midway of its length, 

 and fits between the two largest teeth of the pollex. The meri of the 

 ambulatory legs are less than 22 times their width. 



Dlnicnsious. — cj' : Length, 13.5 mm.; exorbital width, 16.6; posterior 

 width, 15.5; superior frontal width, 9.5; dei)th of front, 2; length of 

 merus of fourth ambulatory leg, 8; width, 3.7. 



Type locality. — West Indies, one cT (Copenhagen Mus.). 



Dedicated to Dr. H. F. Hansen. 



