1354 CRUSTACEA. 



From the external surface of the body of a Bonito (Thymnus 

 pelaniys) ; collected in the Atlantic, September 27, 1838, latitude 27° 

 north, longitude 19° 30' west. 



Length, three-eighths of an inch; breadth, two-fifteenths of an inch. 



The length of the carapax is once and a half its breadth. It has 

 no emargination in front. The caudal setae are parallel, and densely 

 plumose ; the setae in the male are longer than the last two abdominal 

 segments. On the front margin of the carapax, there is a minute seta, 

 about one-half the distance from the sucker disks to the centre of the 

 margin. The sucker disks are elliptical. Terminal setae of the ante- 

 rior antennae as long as the joint. The posterior antennae of the male 

 are uncinate at apex, and have a parallel spine on the inner margin, 

 near its centre. In the female, there is no spine posteriorly on the 

 base, and none exterior to it. The maxillae are stout and broad, nearly 

 as in G: arnericanits.*' The first pair of feet have the basal portion 

 about one-fourth shorter than the following part. The second pair 

 very stout ; hand narrowing outward or subconical in shape ; finger 

 not half as long as hand ; no thumb. First pair of natatories with 

 three longish pinnules to apical joint. Posterior thoracic legs long 

 and slender ; the second portion three-jointed. Eyes appearing deep 

 red on a black ground. External ovarian tubes not shorter than the 

 body in the specimens seen.. 



CALIGUS PRODUCTtTS. 



Feminae : — Carapax ovatus; segmento secundo angusto. Abdomen 3- 

 articulatum, segmento primo ad basin perangusto, oblongo, subelliptico, 

 angulis posticis elongate^ crasseque productis, duobus sequentibus prm~ 

 longis linearibus, ano non prominulo. Styli caudales parce oblongi, 

 terminales. Antennos posticce ad basin posticd acutw et extus basin 

 spina munitce. Furcula simplex, brachiis parce diver gentibus, tenui- 

 bus, acutis. 



Female: — Carapax ovate, second segment narrow. Abdomen three- 



* See Plate 93, for figures of the, C. americanus y also the Amer. Jour. Sci., xxxiv. 

 225, 1838. 



