284 RE\ r . T. R. R. STEBBING ON STALK-EYED CRUSTACEA MALACOSTRACA 



Cliallenger was in lat. 37° 49' N., long. 166° 37' W., mid ocean, North Pacific, trawled 

 from the reputed depth of 3050 fathoms, which, as will be seen, exceeds that assigned 

 to the Scotia species, here named out of respect to Mr Stanley Kemp. 



Locality.— -Lat. 39° 48' S., long. 2° 33' E., trawl 2772 fathoms ; Station 468. 



A fragment of another Gennadas was taken at Station 450, lat. 48° S., 9° 50' W., 

 in company with Petalidium foliaceus. It belongs not improbably to Gennadas 

 parvus, Bate. 



Family Leuciferid,e. 



1837. " Leuciferiens," Milne-Edwards, Hist. Nat. Crust., vol. ii. pp. 451, 467. 



1852. Sergesiidee, Dana, U.S. Expl. Exp., vol. xiii. p. 601; " Luciferidse," pp. 636, 668. 



1905. ,, Stebbing, Gilchrist's Marine Invest., "S.A. Crust.," part iii. p. 80. 



Under the last reference an extended notice is supplied of the bibliography of 

 this family, in which the primary genus bore the preoccupied name Lucifer, changed 

 to Leucifer by Milne-Edwards. 



Genus Petalidium, Bate. 



1881. Petalidium, Bate, Ann. Nat. Hist., ser. 5, vol. viii. pp. 172, 194. 

 1888. ,, Bate, Rep. Voy. " Challenger," vol. xxiv. p. 348. 



1896. „ H. J. Hansen, Pr. Zool. Soc. London, p. 936. 



1903. ,, H. J. Hansen, Pr. Zool. Soc. London, p. 52. 



Hansen accepts two species for this genus, P. foliaceus, Bate, and P. obesus 

 (Kroyer), the former having no branchia above the fourth perseopod, but the latter 

 having at least a rudimentary one in that position. He considers that Petalidium 

 is distinguished from Sergestes chiefly by the structure of the pleurobranchial plumes, 

 feebly developed on the second maxilliped, most developed over the first and second 

 perseopods, but less so over the third maxilliped and third perseopod. The pleuro- 

 branchial plumes in Petalidium, he points out, have a much lower number of rows, 

 a much lower number of plates in the rows, with the plates much larger, curved 

 upwards, and looking much more independent than those in Sergestes. 



Petalidium foliaceus, Bate. 



Plate XXVIII. 



1881. Petalidium foliaceum, Bate, Ann. Nat. Hist., ser. 5, vol. viii. p. 194. 



1888. „ ,, Bate, Rep. Voy. " Challenger," vol. xxiv. p. 349, pi. lx. 



1896. ,, „ Hansen, Pr. Zool. Soc. London, p. 936. 



1903. ,, ,, Hansen, Pr. Zool. Soc. London, p. 52, pi. xi. fig. 1, a-g. 



Almost all the figures of this rare species had been drawn before I realised its 

 identity with that partially described by Bate and Hansen. Attention may be 

 called to the agreement in this plate with Hansen's fig. la of the rostrum. Bate 

 had already noticed the small tubercle .adjoining the dark pigment of the eye. 

 Hansen notes as at least sometimes present another tubercle, exceedingly small, 

 lower down, both being represented in his fig. Id, and well seen in the Scotia speci- 



