422 REV. T. E. R. STEBBING ON AMPHIPODA FROM 



Fam. MELPHIDIPPID^. 



Oammarus spinosiis Goes, 1866, transferred to 31elphidippa by Boeck iu 1871, is 

 •distinct from Gammariis spinosiis Lamarck, 1818. It may now be called Melphidippa 

 Goesi. 



Neohela serrata Stebbing, 1888, should be called Melphidippa serrata. 



Fam. GAMMARID^. 



Pakacrangonyx, n. g. 



All the side-plates shallow. Eyes rudimentary. First antennae longer than the 

 second, with small accessory flagellum. The pleopods abnormal, having only one ramus. 

 The third uropods with very small inner ramus. Telson entire. 



The type-species is Paracrangonyx compactus (Chilton), 1882, from wells in New 

 Zealand. 



Apocrangonyx, n. g. 



Eyes wanting. First antenna? longer than the second, with small accessory flagellum. 

 The third uropods rudimentary, without rami. Telson entire. 



The type-species is Apocrangonyx lucifugus (Hay), 1882, from a well in Illinois. 



Hyalellopsis, n. g. 



Body smooth. Fourth to sixth pleon-segments very short. AntenniB short, first rather 

 the longer, with one-jointed accessory flagellum. Fifth pcra^opod short, with very large 

 second joint. Uropods short, the third uniramous. Telson small, rounded. 



The generic name alludes to the likeness between this genus and the Orchestid Syalella 

 in the caudal part of the animal. 



The type-species is Hyalellopsis Czyrnianskii (Dybowsky), 1874, from Lake Baikal. 



Gen. Pallasea Bate, 1862. 



In this genus I place : — 1. Gammarus asper Dybowsky, 1874, distinct from Gam- 

 marus asper Dana, 1852, giving it the new name Pallasea Bybotoskii ; 2. P. Beisnerii 

 (Dybowsky), 1874; 3. P. cancellus (Pallas), 1772; 4 P. Gerstfeldtil Dybowsky, 1874; 

 5. P. quadrispinosa Sars, 1867 ; 6. P. Kesslerii (Dybowsky), 1874 ; 7. P. baikali, a new 

 name for Gammarus LovenU DyboAvsky, 1874, which is distinct from Gammarus 

 Looeni Bruzelius, 1858 ; 8. P. BrandtU (Dybowsky), 1874; 9. P.Grubii (Dybowsky), 

 1874 ; 10. P. cancelloides (Gerstfeldt), 1858. All these species of Pallasea occur in 

 Lake Baikal. 



