42 DR. R. V. WILLEMOES-SUHM ON SOME ATLANTIC 



rounded claw, which fits into an excision at its top. The second gnathopod (fig. 12) is 

 perfectly leg-like. Its tarsus, like that of the following pereiopoda, is not subjointed, as 

 in Mysis and Gnathophausia, though there are hairs at intervals on it as in those Crus- 

 taceans. 



The five pereiopoda are all very much alike ; only the fifth is somewhat shorter than 

 the rest. I have only drawn the third (fig. 13). 



At the base of all the gnathopoda and pereiopoda we find breeding-lamellae (fig. 1, and 

 figs. 12 & 13), the posterior ones nearly as long as the legs. This is a character not 

 found in any other Mysids, and, among all the Schizopods, hitherto only known in the 

 Lophogastridse. 



The rings of the pleon are perfectly smooth, and do not present any thing particular. 

 The sixth segment is longer than the rest. The five pairs of pleopoda are only rudi- 

 mentary and exceedingly small (fig. 14) ; they consist of a small basal joint and only one 

 ramus. The last ones, especially the fifth, are longer than the first. 



The tail (fig. 1 a) is formed by the telson, which shows a little excision and two appen- 

 dages on each side, the exterior one of each pair jointed. 



Branchial are entirely wanting. 



The male differs very much from the female. Its soft and free carapace is much shorter, 

 not much more than f of the total length ; for in a specimen of 37 millims. it has a 

 length of 10 millims. Thus the last two segments of the pereion are entirely uncovered ; 

 while several of the preceding ones are laterally uncovered, the upper part of the cara- 

 pace being much longer than its lateral parts. 



Very extraordinary are the prehensile organs of the male — the first antenna, the pal- 

 pus mandibularis, the maxilliped, and the first gnathopod — altogether forming a for- 

 midable prehensile apparatus (fig. 2). 



The funiculus of the first antenna is enlarged, and all the joints are elongated ; it 

 has a length of 10 millims. Its flagella, however, are of ordinary size, the exterior 

 one being not enlarged at the base. The second antennae (fig. 2, a 3 ) do not differ 

 from those of the female. The principal prehensile organ is the palpus mandibular 

 (fig. 2,pm), the second and third joints of which are enormously enlarged, and the third 

 armed with strong seta?. The maxilliped (fig. 15) and the first gnathopod (fig. 16) have 

 enlarged joints, and are terminated by strong claws. At their inner side is the lamellar 

 appendage (figs. 15 & 16, la), which we found in the female only in the maxilliped. 



Unfortunately the only male which we caught has lost the second gnathopod and 

 the first pereiopod. The second pereiopod is terminated by a tuft of hairs instead of a 

 claw (fig. 2, prp 2 ). The three last ones do not differ from those of the female, except by 

 being somewhat more slender. 



In the male the pleopods are more perfect (fig. 17) ; for, besides being stronger, they 

 have two rami, one of which is broad and bordered at its rounded top with hairs, the other 

 pointed and nearly filiform. The last pleopoda are longer than the preceding ones. 



The telson of the male (fig. 2 a) does not show such a deep excision as that of the 

 female. 



No traces of branchiae are to be seen. 



