54 BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



" The second gnathopods resemble those of Sphyrapus tudes^ but the 

 basos is narrower, being only slightly broader than the following 

 joints: the meros has one distal spine on the front margin, the wrist a 

 row of five spines, and the hand the same number; the linger is much 

 curved, slender, and its margin smooth. 



''In the first perj\?opods the wrist is a little dilated, the hand flat, 

 long, curved, with seven slight spines on the front margin and much 

 ciliated on both margins. 



"The second pera^opods are shorter than any except the last; the 

 third have the hand short, distally dilated, and then surrounded by a 

 fence of biserrate spines of varying lengths. The fourth and. fifth 

 pairs are similar in form, but the fifth is smaller than the fourth; the 

 wrist is longer than the hand, which is small, ciliated, and has two 

 long spines near the base of the finger. 



"The uropods have the peduncle as long as the segment, minus its 

 produced apex, and a little dilated distally; the inner branch is long, 

 with about 15 articulations, which vary irregularly in length; the outer 

 branch is very slight and composed of 3 articulations. Judging from 

 the spirit-preserved specimens the uropods in this species would seem 

 to be carried divergently, not following behind parallel to each other. 



" Sp/ii/rapKS malleolus may at once be distinguished from its allies, 

 not only by the form of the gnathopods, but by the rudimentary con- 

 dition of the inner flagellum of the upper antenna?, which is reduced 

 to an unjointed minute tubercle and by the spine-formed wings of the 

 second segment of the pleon." — Norman and Stebbing." 



II. CYMOTHOIDEA or FLABELLIFERA. 



Legs of the first pair not cheliform. Uropoda lateral and forming 

 with the last segment of the abdomen a caudal fan. Pleopoda for the 

 most part natatory. 



ANALYTICAL KEY TO THE FAMILIES OP THE CYMOTHOIDEA OR PLABELLIPERA. 



a. Legs in the adult in six, apparently only in five pairs Family III. Gnathiid.e 



(/. Legs in the adult usually in seven pairs. 



h. Uropoda lateral and superior, outer branch arching over base of telson. Body 



cylindrical, narrow, elongated Family IV. Anthurid.e 



J/. Uropoda lateral. 



r. Abdomen usually composed of six segments. 



d. Uropoda with both branches well developed; mostly lamelliform. 

 e. >> Maxillipeda with the palp free, the margins of the last two articles more 

 or less setose, never furnished with hooks. 



« Trans. Zool. Soc. Lond., XII, 1886, pp. 98-99. 



'' Hansen's analytical key as translated by Stebbing has been inserted between 

 points e and d^. See Hansen, Vidensk. Selsk. Skr., 6th ser., natur. og Math. Afd. V, 

 1890, p. 317, and Stebbing, Hist, of Crustacea, 1893, pp. 340-341. 



