JASSIDAE 241 



Remarks. These small specimens belong to the genus Ampithoe, but it would be 

 unwise to identify them definitely with Dana's species, which apparently is still 

 awaiting precise diagnosis. 



The 2nd gnathopod resembles that figured by Kunkel (1910, Trans. Conn. Ac, xvi, 

 p. 90, fig. 35) for rnbricata from Bermuda. The inner lobe of maxilla 1, however, has 

 four setae and thus conflicts with typical rnbricata. The mandibular palp, moreover, is 

 slender, the 3rd joint not apically expanded. 



Family JASSIDAE 

 Stebbing, 1906, p. 647. 



Genus Jassa, Leach. 

 Stebbing, 1906, pp. 652, 739. 

 Sexton, 191 1, p. 212. 



Remarks. That falcata is an almost cosmopolitan form, and also that the c?c? are di- 

 morphic, appears to be true. Sexton's investigations formed the basis for this conclusion. 

 But there is no reason why several other "species" should be included under falcata 

 without at least as thorough an investigation, as e.g. ingens,goniamera and zvandeli, and 

 a protest against what seems rather indiscriminate lumping is not inopportune. 



Chevreux has pointed out features separating wandeli horn falcata, and the constancy 

 of these features seems to be confirmed by the present material. The straight hind margin 

 of the 2nd joints of peraeopods 3-5 was a feature specially mentioned by Pfeffer, 

 Walker and Chevreux. This apparently was one of the differences which Chilton (1912) 

 dismissed as being merely what one might " expect to meet in such a very large form ". 

 I do not quite see why it should be expected, and in any case I hold that it is better to 

 keep the ingens form separate from the falcata form for the present. 



The presence of small specimens, with adult <$<$ and ovigerous ??, in the Discovery 

 collection, which are apparently typical falcata, leads to the question as to what are the 

 characters of typical falcata. Without attempting an answer, owing to lack of material 

 from northern waters, attention may be directed here to one character which seems to 

 have been ignored, namely the epistome. 



Sars (1895, pi. ccxii), Chevreux (1906, fig. 55), and Chevreux and Fage (1925, fig. 

 352) give frontal views of the epistome and upper lip, but no profiles. This defect should 

 be remedied, and the value of the character tested for specific purposes. The forms here 

 identified as ingens and falcata, and also South African examples attributed to falcata, 

 have a rounded epistomial projection, very different from the pointed triangular process 

 in the Tristan da Cunha specimens here referred to pnsillus. 



Jassa falcata (Mont.). 



Sars, 1895, p. 594, pi. ccxii. 



Stebbing, 1906, p. 654 (pulchella); 1914, p. 371. 



Sexton, 191 1, p. 212, pi. iii, fig. 10. 



Schellenberg, 1926, p. 383 (part). 



Barnard, 1930, p. 392. 



? Monod, 1926, p. 61, fig. 58. 



D v 31 



