i83 DISCOVERY REPORTS 



Genus Heronallenia, Chapman and Parr, 1930 



484. Heronallenia wilsoni (Heron- Allen and Earland)(SG 302) (Plate VIII, figs. 30-32). 

 Two stations: 170, 175. 



Confined to these two stations, where it is rare. The specimens are very fine and 

 typical. 



485. Heronallenia gemmata, sp.n. (Plate VIII, figs. 26-29). 

 Two stations: 385, 386. 



Test free, minute, compressed and slightly biconvex; consisting of about eight 

 chambers in an open spiral, rapidly increasing in size, six of which are in the final 

 convolution. Dorsal surface nearly flat, unpolished but not rough, decorated with a 

 series of low circular bosses which follow the curve of the shell and increase in size with 

 its growth. They have the superficial appearance of inflated chambers. A similar series 

 of smaller bosses appears on the ventral side, which is slightly convex, and they are more 

 conspicuous than those on the dorsal side, because the ventral side is smooth and polished. 

 When a test is examined in fluid, it is seen that these bosses are not chambers but solid 

 columns of shell substance extending right through the test. They are extensions of the 

 septal wall between the chambers. The chambers themselves are curiously shaped; 

 when the test is immersed in fluid, but with the chambers still filled Math air, they 

 appear to be crescentiform and recurved, with a long tongue-shaped process extending 

 backwards from the concave centre of the crescent and passing under the outer 

 curve of the preceding chamber. This cannot be traced after the balsam penetrates the 

 chambers. The aperture is an arched opening on the ventral side, depressed and near the 

 inner edge of the final chamber. The peripheral edge is very slightly produced into a 

 narrow round-edged carina. 



Length o-20-o-23 mm.; breadth o-i7-o-20 mm.; thickness 0-04 mm. 



This very interesting little species occurs at two stations in the deep water of the 

 Drake Strait. Four specimens were found at St. 385 in 3638 m., two of which were 

 subsequently lost by breakage under examination. Two were found at St. 386 in 4773 m. 

 St. 386 is outside the Antarctic convergence line, and St. 385 near the line. 



The species is closely allied to H. [Discorbina) lingiilata, Burrows and Holland, 1896 

 (in J.P. and B. 1866, etc., MFC, 1896, p. 297, pi. vii, figs. 33 a-c). That species which is 

 a well-known fossil of the Australian Miocene and is also found living in Australian 

 seas, is, however, very much larger than H. gemmata, and its bosses are less strongly 

 developed and confined to the dorsal surface, the ventral side being smooth. 



Genus Lamarckina, Berthelin, 1881 



486. Lamarckina haliotidea (Heron- Allen and Earland)(F38i) (Plate VIII, figs. 23-25). 

 One station : WS 204. 



A single megalospheric specimen from St. WS 204 is referred with some hesitation 

 to this species. A study of further specimens is required; it may prove to be a new 

 species, being much flatter than the type. 



