810 CRUSTACEA. 



to ten-jointed, joints oblong, setae few, shorter than joints. Infe- 

 rior antennae about as long as base of superior; flagellum four- 

 jointed, and about as long as fourth basal joint. Hand of first pair 

 triangular, lower angle near base prolonged into an acute tooth. 

 Hand of second pair elongate, palm nearly straight, having an 

 acute tooth near base, and in males, a tooth towards apex. Bran- 

 chiae long, and nearly linear. Third and fourth pairs of feet longer 

 than fifth pair. 



Plate 54, fig. 1 a, male, enlarged ; b, hand of first pair ; c, ibid, of 

 second pair; d, mandible; e, lip; /, second pair of maxillae; g, maxil- 

 lipeds ; h, extremity of abdomen ; i, female, probably of this species ; 

 &, antenna of first pair. 



Rio Janeiro, in ten to twelve fathoms water; taken from the anchor 

 along with various Caprellids, January, 1839. 



Length, two-thirds of an inch. Head and first thoracic segment 

 together but little shorter than second thoracic segment; fifth tho- 

 racic segment somewhat the longest ; seventh very short, but slightly 

 oblong and rounded behind. Eyes large and round. Second joint of 

 base of superior antennae about twice as long as first, and one-third 

 longer than third ; joints of flagellum oblong and slender. First pair 

 of thoracic legs nearly half as long as second pair ; first joint about 

 equal to three following ; hand broadest at base, and with a straight 

 transverse basal margin, extending into the tooth below, this tooth 

 tipped with one or two short spines ; a few short hairs on posterior 

 margin of third and fourth joints. Second pair of legs has a slender 

 basal joint, as long as the segment or a little exceeding it, and as long 

 as hand ; the finger is nearly as long as hand and much curved, rather 

 abruptly so, just exterior to centre; branchia of this pair about half 

 as long as basal joint ; when the finger is closed on the hand there is 

 an interval between it and the palm. The hand of males has the 

 palm somewhat concave, a low convex prominence near its middle, an 

 emargination for the extremity of the finger, with a spine below, and 

 one or two smaller above ; also a tooth near apex. In the female, the 

 hand is narrow subelliptical ; it has a tooth, as in the male, near base, 

 which is the limit of the palm, but the palm is slightly arcuate 

 instead of excavate, and has some small teeth. Third and fourth 



