Amphipods 21 E 



Gnathopods short and strong. Gnathopod 1 ; joints 3-6 about as broad as 

 long; 6th joint with sides parallel; palm nearly transverse, slightly convex and 

 provided with a double row of notched spines and a few bristles. Dactyl 

 reaching to end of palm. Gnathopod 2; 6th joint longer than broad and slightly 

 widening distally; palm oblique, evenly convex and provided with a double 

 row of notched spines and a few bristles; dactyl reaching to end of palm. 



Peraeopods slender; 1st and 2nd shorter than rest; 4th longest, proportion- 

 ately longer in <? ; 3rd, 4th, and 5th peraeopods with 2nd joint moderately 

 expanded and bearing shallow serrations on posterior border; dactyls each 

 bearing a setule on the inner edge near extremity. 



Gnathopod 2, and peraeopods 1-3 each provided with a single, lamellar 

 branchia; peraeopods 4 and 5 each provided with two cylindrical branchiae; 

 pleon segment 1 in 9 with a single, small, cylindrical branchia on each 

 side. 



Uropod 1 longest; peduncle a little longer than the subequal rami. Uropod 

 2 with peduncle as long as the subequal rami. Uropod 3 and telson in their normal 

 position project at right angles to the urosome; uropod 3 in this position not 

 reaching end of telson; peduncle broad and flat, and the single ramus small and 

 triangular with 2 stout spines on outer margin; no spines on peduncle. 



Telson as broad as long; the slightly convex sides somewhat converging; 

 end emarginate, depression reaching about one-third length of telson; lobes 

 each provided at apex with 4 or 5 stout spines. 



Length. 6 mm. 



Remarks. To the middle of the ventral surface of each of the 2nd, 3rd and 

 4th thoracic segments is attached an elongated, papilliform process about half 

 the length of the branchiae. Appendages probably of a similar nature were first 

 observed and described by G. 0. Sars in 1867 in the fresh water species Gam- 

 maracanthus lacustris Sars and Pontoporeia affinis Lindstrom. S. I. Smith 

 in 1874 also observed them in a species of Pontoporeia from the Great Lakes. 

 These appendages, the function of which is not know T n, have apparently been 

 observed only in fresh water species. 



This is the first appearance of the genus Synurella in America; the two 

 other species of the genus having been found in Germany and Russia. The 

 closely related genus Boruta was discovered in Hungary so that in all probability 

 these genera will be found to occur throughout Russia, Siberia and northern 

 North America. 



43. Weyprechtia pinguis (Kroyer). 



1838. Gammarus pingvis KROYER, Danske Selsk. Afh., vol. 7, p. 252, pi. I, f. 5. 

 1906. Weyprechtia pinguis STEBBING, Tierreich, Amph. I, p. 382, and synonymy. 

 1909. Weyprechtia pinguis BRUGGEN, Mem. Acad. Imp. Sci. St. Petersbourg, ser. 8, vol. 18, 

 No. 16, p. 36. 



Station 41c: Bernard harbour, Northwest Territories (outer harbour), July 

 28, 1915, 5 fathoms, sandy mud with many algae; 1 specimen. 



Station 4lu: Bernard harbour, Northwest Territories, end of August, 1915, 

 from stomach of Salvelinus malma Walb.; 16 specimens. 



Colour. Dorsal parts of head and body segments dark vinaceous-brown. 

 Sides of body segments and side-plates mottled with dark vinaceous brown 

 and light grayish vinaceous. Antennas striped with bordeaux and light grayish 

 vinaceous. Gnathopods, peraeopods, pleopods, uropods, and telson light grayish 

 vinaceous. 



Distribution. Arctic ocean (circumpolar). 



