632 THE VOYAGE OF H.M.S. CHALLENGER. 



against the carpos ; the dactylos is broad, short, and continuous with the distal 

 extremity of the propodos ; the coxa supports a short mastigobranchial plate and a 

 branchial plume ; the basis carries at its distal outer extremity a short ecphysis ; each 

 joint is thickly fringed with hairs. 



The second pair of gnathopoda (/) is six-jointed and pediform ; the coxa carries a 

 rudimentary mastigobranchia and a tuft of loug hairs, and the basis a rudimentary 

 ecphysis reduced to a tubercle ; the ischium is loDg, and the meros longer and more 

 slender ; the carpos is a little shorter than the meros, and fringed with short stiff hairs ; 

 the propodos is terminal, shorter than the carpos, cylindrical, tapering, and fringed with 

 short hairs. 



The first pair of pereiopoda (k) closely resembles the second pair of gnathopoda, but 

 is more slender. The second pair (I) has the right and left appendages unecpial in 

 length, owing to the carpos on the left side being nearly as long again as that upon the 

 right, both are minutely chelate, the chela on the left side being smaller than that on 

 the right. The posterior three pairs correspond in length, form and character, and 

 are peculiar from the great length of the meros as compared with the ischium (m) ; the 

 posterior margin is furnished with a series of strong and conspicuous spine-hke teeth, 

 and the dactylos is laterally compressed. The posterior pair is a little shorter than the 

 preceding. 



The pleopoda in the female have an elongated, flattened, longitudinally bent peduncle, 

 supporting two long, foliaceous branches fringed with long hairs, and subequal in length 

 in all excepting the first pair, which has the inner and anterior branch shorter for the 

 purpose of supporting the ova, whereas in all the others it is free. 



The sixth or terminal pair (r), which forms the lateral plates of the rhipidura, is 

 strengthened down the median line of the outer branch as well as on the outer 

 margin, and possesses a diaeresis, the portion beyond which is narrower than that 

 anterior to it. 



Heterocarpus alphonsi, n. sp. (PI. CXII. fig. 1). 



Carapace furnished with five carina?, of which the median is produced to a rostrum 

 that is one and three-fourths longer than the carapace ; it is armed dorsally with some 

 large teeth, of which the posterior two stand near together upon the gastric region, and 

 the most anterior a little distant from the apex of the rostrum ; the under side is armed 

 with eleven teeth, of which the anterior is subapical and the posterior in advance of the 

 ophthalmopoda. The outer canthus of the orbit is armed with a strong tooth, which is 

 not confluent with the upper lateral carina, and the infero-lateral angle is also armed 

 with a short tooth, that is confluent with the lower lateral carina. 



The first two somites of the pleon are smooth, but a distinct dorsal carina commences 



