18 EEV. T. E. E. STEBBING — BISCATAN PLANKTON : 



Fam. SciNiB^. 



1849. Corophida (part.), Dana, Amer. Journ. Sci. per. 2, vol. viii. p. 140. 



1853. Curophida (subfam. Clydonince), Dana, U.S. Expl. Exp. vol. xiii. pp. 829, 831. 



1862. Corophiida (subfam. Corophiides) , Bate, Brit. Mus. Catal. Amph. pp. 233, 273. 



18G2. Hyperida, Bate, Brit. Mus. Catal. Amph. p. 308. 



1877. CorophiidcB (subfam. Clydonincp), Streets, Contributions Nat. Hist. Hawaiian and Fanning 



Islands and Lower California, p. 124. 

 1882. Clydoniidcp, Sars, Cliristiania Vidensk. Forliandlingerj No. 18, p. 20. 



1887. Ttjronidcf, Bovallius, Bihang t. K. Svensk. Vet.-Ak. Handl. Bd. xi. No. 16, p. 3 ; K. Sveiisk. 



Vet.-Ak. Handlingar, Bd. xxi. No. 5, p. 3. 



1888. Scinida, Stebbing, ' Challenger ' Araphipoda, Reports, vol. xxix. p. 1270. 



1889. Fortunate, Chun, Math. u. Naturw. Mittheilungen Ak. Berlin, Bd. xlv. p. 535 (345). 



1889. Scinidce, Chun, Zool. Anzeiger, xii. Jahrg. pp. 286, 308. 



1890. Scinida, Sars, Crustacea of Norway, vol. i. p. 18. 



1895. Scinida, Stebbing, Trans. Zool. Soc. London, vol. xiii. pt. 10, p. 349. 



1896. Scinidte, Garbowski, Denkschr. k. Akad. Wiss. Bd. Ixiii. (Ber. Comm. f]rforsch. ostl. Mittel- 



mceres, flinfte Reilie, p. 39). 



1900. Scinidte, Chevreux, Amphipodes de I'Hirondelle, p. 12l. 



1901. Scinidce, Vosseler, Amphipoden der Plankton-Exp. pt. i. p. 100. 



Head usually broader than long, with eyes, when present, small and distant. Pleon 

 narrower than persaeon, its fifth and sixth segments coalesced, and telson small. Eirst 

 antennae large, tapering, with little flexibility, attached at the front corners of the 

 head. Second antennae attached below and behind the first, variable with age and sex. 

 Mandibles without molar. First and second maxillae well developed. First and second 

 gnathopods simple, slender. Of perseopods usually third pair longest and fifth shortest; 

 fingers acute, not retractile. Inner branch of uropods usually coalesced with the 

 peduncle. 



The definition of the family is here modified to admit the new genus Arclueoschia, 

 Avhicli has a mandibular palp, and the new genus JParascina, in which the maxillae are 

 distinctive and the uropods show a clear demarcation between inner ramus and peduncle. 

 Future discoveries will probably justify the withdrawal of Archceoscina from its present 

 position to form the type of a new family Archaeoscinidae. For the present the genera 

 of Scinidae may be distinguished as follows : — 



^ Mandibles with palp 1. Archceoscina. 



o 



*- Mandibles without palp. 2. 

 Palp of first maxilla extremely broad, inner plate of second maxilla broader than 



\ outer 2. Parascina. 



] Palp of first maxilla not very broad, inner plate of second maxilla narrower than 

 V outer. 3. 



r Dorsal carina produced into teeth 3. Acanthoscina. 



(.Segments of trunk without dorsal teeth 4. Scina. 



Acanthoscina was instituted by Vosseler in 1901 for a species, A. serrata, wliich he 

 supposed to be new. Dr. Vosseler happened at the time to be unacquainted with 

 Bcina acanthodes, Stebbing, published in the Trans. Zool. Soc. London, in 1895. This 

 he has since recognized as identical with his own A. serrata, and therefore as the type 

 of his new genus. 



