REPORT ON THE CRUSTACEA MACRURA. 337 



Station 232, May 12, 1875; lat, 35° 11' N., long. 139° 28' E.; off Japan; depth, 345 

 fathoms; bottom, green mud; bottom temperature, 41°'l. Trawl and dredge both used. 



Station 235, June 4, 1875; lat. 34° 7' N., long. 138° E.; south of Japan; depth, 

 565 fathoms; bottom, green mud; bottom temperature, 38°"1. Four specimens ; three 

 males, one female. Trawled. 



Station 133, October 11, 1873; lat. 35° 41' S., long. 20° 55' W. ; near Tristan da 

 Cunha; depth, 1900 fathoms; bottom, Globigerina ooze ; bottom temperature, 35°"4. Three 

 male specimens. Length, largest, 85 mm. (3'4 in.); smallest, 41 mm. (1*6 in.). Trawled. 



The external tissue is more firm and rigid than usual in this genus. The rostrum 

 is short and pointed, tapering slenderly ; crest thin and armed with two small teeth ; 

 carina terminating at the anterior margin of the cervical suture, posterior to which the 

 dorsal surface is smooth and even, excepting for a slight carina which commences on the 

 posterior half of the fifth somite, culminates in a small but distinct carina on the middle 

 of the sixth, and is finally lost before it reaches the posterior margin, which is transversely 

 elevated. The telson (fig. lz) is dorsally flattened and laterally compressed, tapering 

 slightly, and armed with three small spines on each side, the first of which is just 

 beyond the middle, and the last subapical ; the spaces between the teeth are fringed 

 with hairs. 



This species is very like Benthesicymus brasiliensis, but may easily be distinguished 

 by its being more slender, by the firmness and rigidity of the external tissue, by the 

 absence of any teeth on the dorsal surface of the pleon, and by the peculiar transverse 

 elevation of the posterior margin of the sixth somite. 



The ophthalmopod (fig. la) is flattened, membranous and flexible, and is furnished on 

 the inner margin near the base with a small tubercle ; it reaches to the extremity of the 

 rostrum, but falls short of that of the stylocerite; it is of a yellowish-white colour, with 

 a transverse line of dark pigment across the base. The ophthalmus is orbicular, and of 

 about the same diameter as the greatest breadth of the stalk. 



The first pair of antennse has the first joint of the peduncle scarcely longer than the 

 ophthalmopod; it is armed on the outer side with a strong sharp stylocerite, that reaches 

 to nearly the extremity of the joint, the outer angle of which is armed with a strong 

 tooth. The second and third joints are short, subecpial, and distally support two long 

 flagella, the multiarticulation of which is very marked. 



The second pair of antennse supports a long scaphocerite, slightly tapering until 

 beyond the external marginal tooth, which falls considerably short of the distal extremity; 

 the flagellum is long and slender, more slender than the smaller flagellum of the first pair. 



The metope is flat and smooth, and the epistoma projects over it in the form of an 

 angular rostrum. 



The synaphipod of the mandibles has both the joints tolerably broad, flat and strong. 



(ZOOL. CHALL. EXP. — PART LII. — 1886.) Eff 43 



