10 S. I. Smith on Brazilian Crustacea. 



front are very long and slender, the length of the median ones exceed- 

 ing slightly the distance between their tips. The teeth of the antero- 

 lateral margin are much longer and slenderer than in spinimaims, the 

 posterior one (lateral spine) being but slightly longer, in proportion 

 to the other teeth, than in that species. The chelipeds are slender 

 and fully as long as in sjnnimanus. The ambulatory legs are long and 

 very slender, those of the first two pairs extending nearly to the mid- 

 dle of the dactyli of tlie clielipeds. 



The sternum is convex in an antero-posterior direction, while in the 

 spinimanns it is quite flat. In the male the terminal portion of the 

 abdomen is narrowly triangular, the penultimate segment being quite 

 narrow and its lateral margins straight or very slightly concave, while 

 in the spinimanvs it is broad and the lateral margins of the penulti- 

 mate segment quite convex. 



The male abdominal appendages of the first pair are very different 

 in the two species. In both they are stout and separated by quite 

 a broad space. In the sp'n^imanus they reach beyond the middle of 

 the penultimate segment of the abdomen, the thick basal portion cui'v- 

 ing strongly inward from the base, the slenderer portion at first di- 

 rected nearly straight forward, then curved strongly outward, and the 

 tips inward again. In the Ordwayi they are much shorter, reaching 

 but slightly beyond the antipenultimate segment of the abdomen, and 

 have but a single curve, curving inward from the base, then outward 

 to the tip. 



Length of carapax in the single specimen, 37*0™'" ; breadth of car- 

 apax, 61-8"""; ratio of length to breadtli, 1 : 1*67 ; breadth excluding 

 lateral spines, 48'0"'"' ; ratio of length to this breadth, 1:1-29; greatest 

 length of merus segments of chelipeds, 3 TO'""'; length of hand, right, 

 47*2, left, 47*0'""'. A male specimen of A. spinimanus from Florida 

 gives the following : — length of carapax, 40-4'"™ ; breadth of carapax, 

 69-5""" ; ratio of length to breadth, 1 : 1-72 ; breadth excluding spines, 

 58-5'"™ ; r.atio of length to this breadth, 1 : 1-44. 



This species differs from the figure of Neptunus crucntatiis (A. Ed- 

 wards, op. cit, p. 326, pi. 31, fig. 2) in having much longer chelipeds, 

 the merus projecting much farther beyond the sides of the carapax, 

 and the hands when folded in front lapping by each other considerably. 

 The teeth of the front and of the anterolateral margin are very much 

 more slender and prominent than in his figure. And m the descrip- 

 tion of the crxtentatus no mention is made of the smooth and highly 

 iridescent spaces on the supero-exterior surface of the hand, which is 



