REPORT ON THE CRUSTACEA MACRURA. 389 



Ophthalmopod (fig. 3«) half the length of the first joint of the first pair of antennae, 

 which is slightly excavated on the upper surface, and is free from any hirsute fringe. 

 Styloeerite reduced to a pointed bulb at the base. Second joint half the length of the 

 first and a little longer than the third (flagella broken off). 



Second pair of antennas furnished with a scaphocerite that reaches to the extremity 

 of the peduncle of the first pair (flagellum wanting). 



First pair of pleopoda very long, single, slender; second and succeeding, pairs 

 biramose. 



Length (female), 63 mm. (2*5 in.). 



Habitat— Station 170, July 14, 1874; lat. 29° 55' S., long. 178° 14' W.; off the 

 Kermadec Islands ; depth, 520 fathoms ; bottom, volcanic mud ; bottom temperature, 43°. 

 One specimen, female. Trawled. 



This species closely resembles Sergestes japonicus, but is distinguished by the short, 

 stout ophthalmopod and the large ophthalmus, as well as by the structure of the 

 branchiae, which are represented in the case of each species on the same plate. 



Sergestes atlanticus, Milne-Edwards (Pis. LXVIII. and LXIX). 



Sergestes atlanticus, Milne-Edwards, Ann. d. Soi. Nat., torn. xix. p. 349, Mars 1830. 



„ Milne-Edwards, Hist. Nat. Crust., vol. ii. p. 428, 1834. 



Sergestes frisii, Kroyer, Monograph. Fremstilling af Kraebs. Sergestes, pp. 19, 60, Tab. i. a-v, 



1850. 

 Sergestes arcticus, Kroyer, Monograph. Fremstilling af Kraebs. Sergestes, pp. 24, 60, pi. iii. fig. 

 la-g, pi. v. fig. 16. 

 „ „ Sidney Smith, Rep. Decapod Crust. "Albatross" Dredgings off East Coast 



U.S. in 1884, p. 6, pL xx. figs. 1, 2, 1886. 



Rostrum straight, rudimentary. Ophthalmopoda pyriform, much shorter than the 

 first joint of the first pair of antennae. The ophthalmus is broader than long, without 

 any great distinction from the pedicle, which it does not equal in length, except 

 in the old animals, in which also the ophthalmus becomes very distinct from the pedicle. 



The peduncle of the first pair of antennas is only about one-seventh shorter than the 

 carapace ; the third joint is longer than the second, and equal to or a little longer than 

 the first. 



The peduncle of the second pair of antennas has the last joint somewhat clavate and 

 robust ; it is about one-third the length of the scaphocerite. 



The sixth somite of the pleon is about a sixth of the length of the animal, and 

 about twice as long as deep, much shorter than the fourth and fifth somites combined, 

 and also shorter than the first and second combined, but about four times longer than 

 the telson. 



