REPORT ON THE CRUSTACEA MACRTJRA. 419 



Second pair of antennae with a scaphocerite as long as the peduncle of the first pair, 

 and armed on the outer margin subapically with a small tooth. 



The first pair of gnathopoda is generic in character. 



The second pair is long ; the three proximal joints are long and robust, the next long 

 and slender, and the terminal uiiiarticulate, slender, and fringed with hairs. 



The first pair of pereiopoda is short, slender, and carries a small but strong curved 

 process attached to the posterior margin of the ischium. The other pereiopoda are 

 missing. 



The pleopoda are long and slender, slightly shortening posteriorly. 



The outer margin of the external plate of the rhipidura is armed with a tooth one- 

 third from the base, and distally fringed with short hairs ; the inner margin is fringed 

 with long hairs, as are also both margins of the inner plate. 



Length, 8 mm. (0 - 3 in.). 



Habitat. — North Atlantic Ocean. 



Observations. — This species bears a strong resemblance to Sergestes rinhi, Kroyer, but 

 differs in the following points : — in having the rostrum one-third the length of the 

 ophthalmopoda, or about one-fourth the length of the carapace, instead of being short 

 and rudimentary ; the ophthalnrus planted obliquely on the stalk, instead of being 

 symmetrically even (vide Kroyer's figure, pi. ii. fig. 3); a sharp, projecting, mesial tooth 

 on the ventral surface of the first and second somites of the pleon, and an obtuse pro- 

 jection on the three following somites ; the ophthalmopoda subequal to the peduncle 

 of the first pah- of antennae, instead of not reaching beyond the extremity of the second 

 joint ; a small tubercular process attached to the posterior margin of the ischium of the 

 first pair of pereiopoda, not present in Sergestes rinlcii (Kroyer has figured the appendages 

 separately) ; the terminal pair of pleopoda, which helps to form the rhipidura, armed on 

 the outer margin with a sharp tooth that is nearer the basal articulation than is the 

 extremity of the telson, while that of Sergestes rinlcii is much nearer the distal 

 extremity. 



Sergestes fermerinkii, n. sp. (PI. LXXVI. fig. 4). 



Carapace rather less than a third of the length of the animal. Eostrum smooth, 

 sharp and horizontal, about one-fourth the length of the carapace. Frontal margin 

 produced to a sharp tooth at the outer orbital angle. 



First somite of the pleon dorsally smooth and laterally furnished with a short 

 anteriorly directed tooth or tubercle. Second somite subequal and smooth. Third, 

 fourth and fifth dorsally armed near the posterior margin with a strong tooth ; as is also 



