276 DISCOVERY REPORTS 



longer, the upper lip more turned downwards, and the posterior " thorn" curved more 

 upwards. The lower side is also more deeply sculptured. 



Diacria, Gray, 1842 



Diacria trispinosa (Lesueur), 1821. 



Hyalaea trispinosa, Lesueur (in Blainville, Dictionn. d'Hist. Nat., xxn, p. 82), 1S24. 

 Hyalaea muronata, Quoy and Gaimard, 1827. 



St. 89. Young-fish trawl, 1000 (-0) m. : 3 specimens. 



St. loi. 4-5 m. net, 350-400 (-0) m. : 5 specimens. 



St. 268. I m. net, oblique, 73-0 m. : 3 specimens. 



St. 279. 4 mm. mesh net on trawl, 58-67 m. : i shell. 



St. 288. Young-fish trawl, 250 (-0) m. : 9 specimens; i m. net, oblique, 73-0 m.: 3 specimens. 



The above hauls were all made off the African coast from Cape Town to the Gulf of 

 Guinea . Some of the specimens had hydroids on the shells . The average length was 8 mm . 

 This genus is distinguished by having bilobed fins, a very large apron and neither gill 

 nor lateral appendages. It resembles Cavolinia in the form of jaw, radula and gizzard 

 plates, and in the rest of the internal organization. The posterior end of the shell is pro- 

 longed three or four times as much as in Cavolinia, and is almost straight instead of being 

 bent. It terminates in a little knob, similar to the embryo shell in this position in Cleodora. 

 The lateral points are also very long, are placed at about the centre of the shell and 

 constitute its greatest breadth. They occupy about two-fifths of this measurement. The 

 hinge is not nearly so well defined as in Cavolinia. The shell is chiefly transparent, but a 

 chocolate-brown tinge is usually distributed in the region of the lip. The lower side is 

 not much swollen. 



Distribution. Universal except at the poles. 



Genus Cleodora, Peron and Lesueur, 18 10 



Cleodora sulcata (Pfeffer), 1879. 



Cleodora sulcata, Pelseneer, 1888; Eliot, 1907. 



Over 2000 specimens were caught in hauls made at thirty-four stations at the South 

 Sandwich Islands at soundings of 0-250 m. A few occurred also at South Georgia 

 and between the Falkland Islands and South Georgia at soundings of 0-500 m. 



The specimens measured 2-30 mm. in length. The usual length of large individuals is 

 16-18 mm. With fins fully extended the length may reach 25-30 mm. The fins and apron 

 are generally white, but in hauls made in January and February 1928, at the South Sand- 

 wich Islands (Sts. SS 34, 35, 52, 54 and 58) these portions of the body had a border of 

 chocolate-brown which sometimes spread all over the fins on both sides. The tint be- 

 came paler as the distance from the margin increased. Individuals in which the animal 

 was in a peculiar soft condition, appearing to show degeneration in the cells, occurred at 

 the South Sandwich Islands (Sts. SS 7, 9, 10, 14, 22 and 45). 



