8 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



thoracic feet long — much longer than the succeeding pair. The fifth 

 pair euhirged, and used for prehension ; the extremiti/, or claw, reHemhling 

 that of the Squllla — the movable finger (fifth joint) flexing against the 

 anterior aspect of the palm, which is furnished with teeth. Three pairs 

 of styliform caudal appendages:* the second, or middle pair short, or 

 rudimentary. 



Sexual differences. — Males smaller than the females, and more robust. 

 In the females the second pair of caudal appendages are rudimentary, 

 almost obsolete; in the males well developed. 



In respect to the antennje and other parts of the body the sexual 

 differences are similar to those observed in Phronima. 



Phronimella elongata, Clans, 



(Plate I, Fig. 4, 4a, 5, 5a.) 



Phronima dongata, Clans, Wiirzburger naturwissen. Zeit-schrift, Wihvbnrg. 1862, III^ 

 IX 247, pi. vi, tig. 6-11 (male and female).— Zeicdchrift f. wisseu. Zoologie, 

 Leipzig, 1S63, XII, p. 193, pi. xix, iigs. 2,3,7 (female). 



rhronlmcUa doufjata, Claus, Zeitschrift f. wisseu. Zoologie, Leipzig, 1872, XXII, pp. 

 333, 336, 337. 



Andiyloni/x hamatus, streets, Bulletin of the National MLL-jenm, No. 7, Wasniugtoa, 

 1877, p. 131 (female). 



Female. — The first joint of the superior antennte short; the second 

 long and with a few auditory hairs at its apex. The first and second 

 juiirs of thoracic feet shorter than the succeeding pairs ; the first shorter 

 than the second, with the fourth joint hardly produced at its posterior 

 distal extremity, the produced portion spine-like; the second pair with 

 the fourth joint elongate and slender, and with the spine on the pos- 

 terior distal extremity often wanting; where it is present it is much 

 smaller than that on the corresponding joint of the first pair. The 

 third pair of thoracic feet extremely elongate, nearly as long as tiie 

 animal, the excessive lengthening being in tlie last two joints ; the 

 bases of the third and fourth x)airs of feet spinous along the posterior 

 edge. The base of the fifth, or prehensile, pair longer than that of the 

 preceding pairs, and spinous on the anterior edge, two or three spines 

 on the posterior edge near the distal extremity; the anterior edge of 

 the second, third, and fourtli joints spinous; the fourth joint enlarged 

 at its extremity, and armed with four or five large teeth, against which 

 the following joint, or finger, impinges; the lowest of the teeth the 

 largest, and touches the finger about its middle; the fifth joint about 

 one-third the length of the fourth, arched; the claws of all the pairs of 

 feet anchylosed with the fifth joint, and fixed at a right angle to it, form- 

 ing a hook, and the apex of the fifth joint slightly produced as a straight, 

 acute spine. The bases of the last two pairs somewhat club-shaped, 



* Clans stales that there are " only two pairs of styliform caudal a[)pendages." 

 This is true of the female, but not of the male. In one of his plates, where the cau- 

 dal extremity of a male is given, the three pairs of styliform appendages are very 

 clearly represented. 



