/ 



80 "TERRA NOVA" EXPEDITION. 



antennal scale slightly outreaches the antennular stalk, narrowing to a rounded end, 

 which is barely outreached by the subterminal spine. All the flagella are broken short 

 in the specimen. The third maxilliped outreaches the antennal scale by the whole of 

 its slender, pointed end-joint and a small part of the penultimate joint, which is about 

 .one-third longer than the end-joint. The first leg slightly outreaches the antennal 

 stalk. Its fingers are not quite twice as long as the palm, its wrist longer than the 

 hand. The second leg reaches the end of the antennular stalk. The third leg is 

 missing on both sides of the specimen. The fourth leg nearly reaches the end of the 

 first joint of the antennular stalk. The fifth leg slightly outreaches the whole stalk. 

 The legs are smooth save for a few scattered hairs. The petasma is slender and simple, 

 and probably not fully formed in the specimen. The abdominal segments are simple 

 in shape, but the sixth bears a spine in the middle of the hinder edge. The telson is 

 shorter than either branch of the uropods. It is slender and ends in a sharp spine. 

 Its upper surface is marked by a deep groove to within about one-third of its length 

 from the free end, where two strong, fixed lateral spines stand. 



Length, 7 cm. 



One specimen, from Station 96. 



Family SEEGESTIDAE. 

 Sub-family SERGESTINAE. 



2. Sergestes atlanticus, H. M.-Edw., 1830. 



Sergestes atlanticus, H. M.-Edwards, Ann. Sci. Nat. (1) XIX, p. 349, pi. X,figs. 1-9 ; Hansen, 

 Proc. Zool. Soc. Lond., 1896, p. 949. 



The Expedition took no adult meml)ers of this species, but at three stations in the 

 North Atlantic there were obtained specimens pf S. ancyloj)s, Kr., 1859, which, 

 according to Hansen, is a young form of S. atlanticus. 



Ten specimens were taken at Stations 45, 46, 66. 



3. Sergestes jKtcijicus, Stm., 1860. 



Sergestes pacifcus, Stimpson, Proc. Acad. Philadelphia, 1860, p. 45; Ortmann, Ergebu. 

 Plankton-Exped., II, G, b, p. 30 (1893). 



This form has not hitherto been recorded from the Atlantic. Hansen mero'es it in 



ti^ 



S. atlanticus, but according to Ortmann the possession of a supraocular spine diff'er- 

 entiates it from the latter species, and this is borne out by the figures of Bate 

 (" Challenger" Macrura, pi. XVIII) and Kr><yer {S.frisii, K. Dansk. Videnskab. Selsk. Skr. 

 (5) IV, pi. I), which both show S. atlanticus without the spine. A similar case occurs 

 among the Pontoniinae, where Periclimenes spiniferus differs from P. jx'titthouarsi only 

 by the possession of a supraocular spine. 



Eight specimens were taken at Stations 49, 50, 68. 



