1606 THE VOYAGE OF H.M.S. CHALLENGER. 



which is nearly smooth on the outer margin, denticulate on the inner ; the inner ramus 

 longer than the outer, denticulate on both margins ; the inner margin of the peduncles 

 is shallowly serrate and has three teeth at the apex. The peduncles of the first and 

 second pairs have the apex of the inner margin acutely produced ; the apices of all the 

 rami are produced into long sharp points. 



Telson apparently coalesced with the preceding double segment, carinate, nearly half 

 the length of the head, longer than the first uropods, about four and a half times as 

 long as its greatest breadth, tapering far beyond all the uropods to an acute point. It 

 should be mentioned that fig. T., representing the telson, is drawn to a larger scale 

 than fig. CD., representing the dorsal aspect of the head. 



Length of the outstretched animal a little over an inch. 



Locality. — June 20, 1875, North Pacific; lat. 35° 35' N., long. 150° 50' E.; surface 

 temperature, 69° - 7. One specimen, female. 



Genus Rhabdosoma, Adams and White, 1 847-48. * 



1840. Oxycephalic d^ars), Milne-Edwards, Hist. Nat. des Crustacea, t iii. p. 101. 



1847. Rhabdosoma, "White, List of Crust, in Brit. Mus., p. 130. 



1848. „ Adams and White, Zool. of Voy. of H.M.S. " Samarang," p. 63. 

 1852. „ Dana, Arner. Journ. Sci. and Arts, ser. 2, vol. xiv. No. 41. 

 1852. „ Dana, U.S. Explor. Exped., vol. xiii. pi. ii. p. 1009. 



1858. Macrocephalus, Spence Bate, Ann. and Mag. Nat. Hist., ser. 3, vol. i. p. 361. 



1862. Rhabdosoma, Spence Bate, Brit. Mus. Catal. Aniph. Crust., p. 344. 



1871. „ Claus, Unters. iiber den Bau und die Verwandsohaft der Hyperiden. 



1878. „ Streets, Proc. Acad. Nat. Sci. Philad., p. 286. 



1879. ,, Claus, Die Gattungen und Arten der Platysceliden, pp. 43, 49. 

 1884. „ Claus, Lehrbuch der Zoologie, trans, by Sedgwick, p. 455. 



1886. ,, Gerstaecker, Bronn's Klassen und Ordnungen, Bd. v. Abth. ii. p. 487. 



1887. Rhabdonectes, 1 Bovallius, Systematical List of Amph. Hyper., Bihang till K. Svensk. 



Vetensk. Akad. Handl., Bd. 11, No, 16. p. 39. 

 1887. Rhabdosoma, Claus, Die Platysceliden, pp. 68, 73. 

 1887. „ Giles, On Six new Amphipods from the Bay of Bengal, Journ. Asiat. Soc. 



Bengal, vol. lvi. pt. ii. No. 2, p. 219. 



For the original definition of Oxycephalies, see Note on Milne-Edwards, 1830 (p. 143). 

 For Rhabdosoma, see Note on Adams and White, 1848 (p. 225). For the definition of 

 Macrocephalus, see Note on Spence Bate, 1858 (p. 307). For the definition of 

 Rhabdonectes, see Note ou Bovallius, 1887 (p. 591), and for a short definition of 

 Rhabdosoma, see Note on Claus, 1879 (p. 493). 



Claus' fuller account of the genus is to the following effect : — 



'' The proximal section of the head is elongate, linear, swollen in front to fhe 



1 BovaUius, in his Systematical List, 1887, says with regard to Elmbdonectes, "the name has been substituted for 

 the old name Rhabdosoma, as this latter was already preoccupied by Dumeiil for an Ophidian genus." but Dumcril's 

 genua is llabdosoma and its date 1853, see Mem. Acad, des Sciences, Paris, t. xxiii. p. 440. 



