558 



of Sp. Bate is identical with this genus. It comprises 3 Norwegian 

 species, to be described below, one of which is now for the first time 

 established. The Rev. Mr. Stebbing has also added 4 new species from 

 the Challenger Expedition. 



10. Gammaropsis erythrophthalma, Lilljeborg. 



(PI. 198). 



Gammarus (Gammaropsis) erythrophthalmus, Lilljeborg, Kongl. Svenska Vet. Akad. Handl. 



1854, p. 455. 



Syn.: Eurystheus tridentatus, Sp Bate. 

 > Autonoe erythrophthahna, Bruzelius. 

 Eurystheus erythrophthalmus, Sp. Bate. 



Body moderately slender and somewhat compressed, with evenly 

 rounded back. Cephalon about the length of the first 2 segments of mesosome 

 combined, lateral corners terminating in an acute angle. First pair of coxal 

 plates rather small, and rounded quadrangular inform; the 3 succeeding pairs 

 a little deeper than the corresponding segments, 2nd pair in male being the 

 largest; 5th pair with the anterior lobe scarcely as deep as the preceding 

 pair, and evenly rounded. Last pair of epimeral plates of metasome produced 

 at the lateral corners to a small dentiform projection, posterior edge but 

 slightly curved. Eyes rather large, oval reniform, with bright red pigment. 

 Superior antennae considerably exceeding half the length of the body, 2nd 

 joint of the peduncle the longest, 3rd joint about the length of the 1st. 

 flagellum not attaining the length of the peduncle, and composed of about 

 15 articulations, accessory appendage rather fully developed, exceeding in 

 length the last peduncular joint, and 6-articulate. Inferior antennae a 

 little shorter than the superior, with the flagellum somewhat exceeding half 

 the length of the peduncle. Both pairs of antennae clothed posteriorly with 

 fascicles of rather long bristles. Anterior lip produced in front to an 

 obtusely conical projection. Anterior gnathopoda with the carpus slightly 

 expanded in the middle, being subfusiform in outline, propodos about same 

 length, and nearly triangular in form, with the palm rather oblique, and 

 about the length of the hind margin, dactylus very slender. Posterior 

 gnathopoda in female much stronger than the anterior, with the propodos 

 rather large, about twice the length of the carpus, and oblong oval in form, 

 palm very oblique, and defined below by a very slight angle carrying a 

 slender spine, its edge minutely serrulate, and produced in the middle to 



