157 



small claws. Second segment of pereopods V armed on both margins 



with thin pointed spines 3. Spinoscina Bow. and Grun. 



— First two somites of pereon not fused. Inner lobes of maxillipeds 

 absent. Pereopods III-VII with retractile claws. Posterior margin of 



2nd segment of pereopods V bears blunt festoonlike lobes 



2. Ctenoscina Wagl. 



1. Genus Scina Prestandrea, 1833 



Prestandrea, 1883: 8. 



Somites I and II of the pereon are free; the pereon and pleon lack 

 dorsal denticles or spines; the dorsal keel may be present or absent. The 

 eyes are highly reduced but generally perceptible. Antennae II in males are 

 well developed, multisegmented, thin, and whiplike; in females they are 

 reduced, very small, and one-, two- or three-segmented. Maxillae I have 

 a single-segmented palp which is longer, equal to, or just slightly shorter 

 than the outer lobe. Maxillae II have separated lobes. The maxillipeds have 

 developed outer lobes and fused inner lobes; the latter are reduced to some 

 extent but always present. The coxal plates are free. Pereopods I and II 

 are simple; in pereopods V the outer distal angle of the 2nd segment is 

 extended into an acute denticle that is usually larger than the 3rd segment; 

 pereopods V-VII are without retractile claws. Pereopods VII are shorter 

 than pereopods VI. The telson is free. The oostegites have marginal setae. 

 The gills are located on pereon somites II-VI or III-VI. 



Type species: Scina ensicome Prestandrea, 1833 nom. dub. 



To date, 32 species of Scina have been described. Some groups of 

 closely related species are apparent among them, which possess an entire 

 series of common morphological features. These groups, named after the 

 typical species, are: 



1. Group crassicornis. Includes S. crassicornis, S. curvidactyla, S. curi- 

 lensis; are close to them S. incertas, S. langhansi, S. vosseleri, and 

 possibly S. borealis are close to it. 



2. Group spinosa. Includes 5. spinosa, S. indica, and S. pubera; 

 S. stebbingi is close to it. 



3. Group marginata. Includes S. marginata and S. submarginata. 



4. Group rattrayi. Includes S. rattrayi, S. antarctica; S. oedicarpus, 

 S. wolterecki, S. wagleri, S. stenopus. 



5. Group tullbergi. Includes S. tullbergi, S. similis, S. nana, S. setigera, 

 S. excisa, and S. damasi. 



6. Group latifrons. Includes 5. latifrons, S. pusilla, and S. typhlops; the 

 most unusual of the Scina species, 5. chelata, is closer to it in several 

 features. 



Finally, S. lepisma, S. inermis, and 5. alberti stand out independently. 



