130 PROCEEDINGS OP THE AMERICAN ACADEMY 



One small specimen presents an interesting hermaphroditic condition. 

 With the first abdominal appendages of the male is combined a well- 

 formed annulus ventralis of the female ! 



18. C. Harrisonii, sp. nov. 



Male, form I. Rostrum long, narrow, deflexed, excavated ; mar- 

 gins thickened, a little convergent ; acumen of moderate length, tri- 

 angular, acute ; marginal spines short, obtuse, often obsolescent. 

 Carapace flattened above, coarsely punctate, granulate on the sides ; 

 post-orbital ridges prominent, sulcate without, with acute anterior 

 spine ; antero-lateral margin notched at base of antenna ; cervical 

 suture not sinuate, interrupted on the side ; lateral spine small, acute ; 

 branchiostegian spine obsolete ; areola at least one half as long as the 

 distance from the tip of the rostrum to the cervical groove, of moder- 

 ate width, punctate, the dots tending to a biserial arrangement in the 

 middle portion. Abdomen as long as the cephalo-thorax ; telson long, 

 posterior margin rounded, posterior margin of basal segment bispinous 

 on each side. Basal segment of antennule with an internal, sub-apical, 

 inferior spine. Antennaj as long as the body ; second segment armed 

 with a short, acute, external spine ; scale as long as the rostrum, of 

 moderate width, widest near the middle, thence tapering to the acute 

 external, apical spine. Anterior process of epistoma with convex 

 sides, apex blunt or truncate. Third pair of maxillipeds hairy within. 

 Chelipeds of moderate length, thick ; chela large, broad, coarsely punc- 

 tate above and below, inner margin of hand with two or three rows of 

 depressed ciliate tubercles ; fingers costate and punctato-lineate, gaj)- 

 iug, inner margins with rounded tubercles ; movable finger incurved ; 

 carpus punctate above, armed with an acute median internal spine 

 and two inferior spines (a large median and a minute external). In 

 some specimens there are one or two small antennal basal tubercles. 

 Meros smooth without, two obliquely-disposed superior sub-apical 

 spines ; of the biserial inferior spines only a few of the distal ones in 

 each row are developed. Distal end of second pair of legs ciliate. 

 Third segment of third pair of legs hooked. First pair of abdominal 

 appendages short, reaching to the base of third pair of legs, thick, split 

 for a short distance from the tip ; outer part longer than the inner ; 

 tips recurved, brown-horny. 



Female. Fingers less widely gaping, outer one ciliate within at 

 base. Abdomen broader. Sternum between fourth thoracic legs, 

 smooth. Annulus ventralis a transverse ridge, thickest in the middle, 

 where there is a rounded tubercle divided longitudinally by a sinuous 



