MYSIDEA. 577 



Carapax acutely rostrate, behind dorsally excavate and angles rounded, 

 beak rather longer than the eyes. Eyes very large, orbicular, 

 but little narrower than thorax. Base of inner antennae very long, 

 hardly shorter than carapax, process of first joint shorter than the 

 joint following. Last segment of abdomen nearly half shorter than 

 caudal lamellse, truncate, naked. 



Plate 45, fig. 4 a, animal, enlarged ; J, caudal extremity. 



Pacific, among the Kingsmills Group, near Charlotte's Island. Col- 

 lected, April 21, 1841. 



Length, between two and three lines. Colourless. First joint of 

 base of first antennae half whole length of base, and extends about 

 half its length beyond the eyes. Next two joints equal, oblong, a 

 few short hairs at apex of each. Two branches at apex, rather 

 shorter than preceding joint. 



Legs of thorax were not full grown ; abdominal appendages perfect, 

 natatory, setae short. A minute, clear globule in a projection at base 

 of five pairs of abdominal legs. The caudal lamellae in the specimen 

 appeared % to be full grown; they were about equal, and nearly twice 

 as long as caudal segment; they were furnished with setse, as usual, 

 and there was no spine at apex of inner lamellae. The caudal seg- 

 ment had no spinules at apex. 



FURCILIA ABBREVIATA. 



Carapax acute restrains, posticd super dorsum parce excavatus angulisque 

 rolundatus, rostro oculis breviore. Oculi medicares. Basis anten- 

 narum internarum brevis; processus articuli primi articulo proximo 

 longior. Segmentum abdominis postremum elongatum, truncatum, 

 apice spinulosum, spinulis externis longioribus ad angulos contigue 

 infixis. 



Carapax acutely rostrate, beak shorter than the eyes, posteriorly over 

 back sparingly excavate, at angles rounded. Eyes rather small. 

 Base of inner antennae short, process of first joint longer than joint 



170 



