NO. I 



POINT BARROW AMPHIPODA — SHOEMAKER 



33 



into a shallow lobe. Telson is without spines. Gurjanova gives 62 m. 

 for the depth of this species. 



Family THAUMATELSONIDAE 

 PROTHAUMATELSON CARINATUM, new species 

 Figure 13, a-c 

 Prothaumatelson Schellenberg, 1931, p. 113. 



Material collected. — In 217 feet, 7.5 miles oflf Point Barrow base, 

 September 6, 1949, i specimen. In 120 feet, off Point Barrow base, 

 September 15, 1948, 5 specimens. 



Fig. 13. — Prothaumatelson carinatum, new species. Female : a, entire animal ; 

 b, gnathopod i ; c, gnathopod 2. 



Schellenberg says of Prothaumatelson that the second gnathopod 

 is chelate and that the mandibular palp has a reduced number of joints. 

 He places Thaumatelson nasutum Chevreux (1913, p. 109) and 

 Thaumatelson inermis Chilton (1912, p. 483) in his new genus. With 

 amphipods as small and fragile as these (2 to 3 mm.) it is in many 

 cases difficult to determine the exact number of joints in some of 

 their appendages. The present specimens from Point Barrow have 

 been placed in Prothaumatelson, although the mouthparts do not 

 appear to agree in all details with Schellenberg's genus. 



Femule. — Head not quite as long as the first two body segments 

 combined; lateral lobes triangular with sharply rounding apex. Eye 

 of medium size. Antenna i, very little shorter than antenna 2, first 

 peduncular joint nearly as long as second and third combined; 

 flagellum about as long as the third peduncular joint and composed 

 of four joints. Antenna 2, fifth joint longer than the fourth; 



