MARINE MOLLTJSCA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 123 



Lacuna abyssicola, sp. n. (Plate, figs. 8, 8 a, 8b). 



L. testa parva, profunde umbilicata, albo-calcarea, epidermide brunnea contecta, fragili, vix solida, 

 nnfractibus 5, quorum apex ipse mire" immtrsus, duobus his proximis cum penultimis tumidulis, ultimo 

 paullum effuso, laevi, omnibus infra suturas canaliculatis et acute spiraliter carinatis, apud basim, circa 

 umbilicum, crassi-carinato carinis binis, sulco interstitial! preedito, apertura rotunda, labro tenui, margine 

 columellari late 1 reflexo. 



Alt. 2, lat. 2-15 mm. 



Hob. Deposit No. 38, dredged March 18, 1904. Lat. 71 22' S., long. 16 34' W., 

 1410 fathoms. Station 417. 



One specimen only, but adult and fairly perfect, save for a slight fracture of the 

 outer lip. It appears nearly akin to L. nautiliformis, Jeffreys, or L. cincta of the same 

 author, from the Atlantic, collected on the Porcupine Expedition, especially as 

 regards the sculpture round the umbilical region, the thickened double carination with 

 interstitial sulcus. Another feature of interest is the curiously immersed nucleus, 

 and the strong canaliculation round the upper portion of each whorl, followed by an 

 acute spiral keel. The substance of the shell is chalky white, covered with a dark- 

 brown epidermis. The specific name proposed is given in consideration of the extreme 

 depth at which it was dredged. 



Lacuna wandelensis, E. Lamy. 



Lacuna wandelensis, E. Lamy, Exped. Antarct. Franfaise commandee par le Dr Jean Charcot : 

 Moll., p. 5, pi. i. figs. 5, 6, 7 (Paris, 1906). 



Hob. Station 325, Scotia Bay, South Orkneys, 9-10 fathoms, on Macrocystis and 

 other large Fuci. 



A very few examples, and all in non-adult condition, belong almost certainly to 

 this species. 



Family Rissoidae. 

 Rissoa deserta, Sm. 



Rissoa deserta, E. A. Smith, Nat. Antarct. Exped. : Nat. Hist., vol. ii. p. 9, pi. ii. fig. 1 

 (1907). 



Hob. South Orkney Islands, Scotia Bay, 9-10 fathoms. Station 325. 

 The specimens are dead, but seem to agree in form with the above species. 



Rissoa (Onoba) filosttia, sp. n. (Plate, fig. 9). 



11. testa pai'Vii, paullum inflata, solidula, parum rimata, anfractibiw 4|, quorum apicales duo Iseves, 

 tumiduli, cseteris ventricosis, apud suturas impressis, arctissime spiraliter tenuiliratis, apertura ovata, alba, 

 labro paullum effuso, baud multum incrassato, fere continue. 



Long. 2, lat. T50 mm. 



Hob. South Orkney Islands, Scotia Bay, 9-10 fathoms. Station 325. 



Allied to several Onobze, mostly described of recent years from deep-sea explora- 



(ROY. soc. EDIN. TRANS., vol.. XLVIII., 349.) 



