78 Addison E. Verrill, 



on the inner side is deeper and joins the posterior impressed line; 

 the distal articular margin is tridentate ; the upper median tooth 

 is small, obtuse, the lateral ones are more acute ; these teeth and 

 the tips of the fingers are often brownish black; dactyl is broad, 

 somewhat flattened from above, arched, with an upper area 

 bounded laterally by a thin ridge above a deep groove, on each 

 side, which meet in an obtuse point at about the distal third, where 

 the tip begins to bend down in a regular curve ; the edge of the 

 groove bears a dense fringe of hairs on each side. It has been 

 described as "boat-bill shaped." The edge of the fixed finger is 

 also fringed with similar hairs ; this finger is bent upward a little 

 near its tip ; both tips are acute ; on the inside, the fixed finger is 

 excavated, while the dactyl has a median carina. 



The rostrum is spiniform, small, thin, nearly straight on the 

 dorsal edge, with no concavity, and usually slopes to the acute tip. 

 which projects but little beyond the orbital edge. Each side of 

 the rostrum there is a narrow and shallow sulcus, ending gradually 

 posteriorly, not abruptly, as in armillatus. The ocular lobe is 

 prominent, obtusely rounded in front, with no tooth or denticle, 

 and there is only a faint emargination of the frontal margin each 

 side of it. 



The second segment of the antennules is about twice as long as 

 the third ; the basal scale is short and rather wide, with a minute 

 spine that does not reach the end of the first segment. Description 

 above is of No. 1830, from Fort Macon, N. C. 



This species can .easily be distinguished from A. ami Hiatus by 

 the rostrum and front, when the chelae are lacking. In this the 

 rostrum is smaller and simply spiniform, having no land form 

 expansion distally, nor is it so broad and triangular at its base ; 

 its upper edge is not concave in a side view, as it is in armillatus, 

 but is nearly straight, sloping distally. The fossae, between the 

 rostrum and the eyes, are narrower, and do not end abruptly, as 

 in armillatus, and are therefore much less conspicuous. 



The orbital lobe or hood is rounded anteriorly without the slight 

 lobe seen in the latter. The front edge of the carapace is therefore 

 less sinuous or indented and lacks the rather deep emargination 

 each side of the carina. 



The antennular scale or stylocerite is short, rather broad and 

 acuminate in both, but most so in hctcrochcclis ; the acute terminal 

 spine of the latter reaches the base of the second segment or beyond 



