48 Bulletin, Vanderhilt Marine Museum, Vol. II 



Family: Raninidae. 



Genus : RANINOIDES H. Milne Edwards. 

 Eaninoides laevis lamarcki A. Milne Edwards and Bouvier 



Plate 9, figs. A, B. and C. 



Type: The type of this species was taken by the ''Blake" West In- 

 dian expedition. 



Name : Burrowing crab ; frog crab. 



Diagnostic characteks : Only species so far recorded from tropical 

 America, Carapace concave, twice as long as wide, lateral margins 

 converging anteriorly, and much more so posteriorly ; one acute lateral 

 tooth somewhat behind the postorbital spine ; rostral tooth triangulate, 

 two submedian shorter teeth ; an acute tooth separated from the rostral 

 area and also from the preorbital by a sinus. First legs chelate, pro- 

 podus armed with four spines ; upper finger with one sub-basal spine. 



Distribution : Known from the West Indian region and also from 

 the Perlas Islands, which latter record is first established by the 

 "Ara" material. 



Habits : Little is known of this peculiar burrowing crab, of which 

 the "Ara" specimens appear to be the third record. It belongs to a 

 family whose members spend the greater part of their time burrowed 

 in the sand with only the eyes and antennae exposed. The feet are fal- 

 cate and form remarkably efficient diggers; even the shape of the 

 body conforms to this habit. When resting, the crab, viewed from the 

 front has an odd, frog-like aspect, hence its common name. 



Material examined: One egg-laden female dredged in 70 fms., 

 southwest of Marquesas Keys, Florida, March 2, 1924; one male and 

 one female taken in the Perlas Islands, February 19, 1928, by the 

 "Ara," William K. Vanderbilt, commanding. 



Technical description: Carapace 24 mm. maximum length, 12.5 

 mm. maximum width, decidedly elongate-ovate, very convex, the 

 frontal margin almost twice as wide as the extreme posterior margin 

 of the carapace, which, however attains its maximum width two-fifths 

 of the length from the frontal margin. The maximum width is twenty 

 percentum greater than the frontal width. The frontal margin is 

 divided into five lobes, of which the median lobe comprises approxi- 

 mately one-half the width of the frontal border and is produced into 

 an acuminate, triangulate median rostral tooth which projects beyond 



