MARINE MOLLUSCA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 123 

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



L. testa parva, profunda umbilicata, albo-calcarea, epidermide bniunea contccta, fragili, vix solida, 

 anfractibiis .5, quorum apex ipse mire immirsus, duobus his proximis cum petiultimis tumidub's, ultimo 

 paullum effuso, Issvi, omnibus infr;l suturas canaliculatis et acute spiraliter carinatis, apud basim, cired 

 umbilicum, crassi-carinato cariuis l)inis, sulco interstitiali prfedito, apertura rotunda, labro tonui, margine 

 columellari late reflexo. 



Alt. 2, lat. 2-15 mm. 



^a6.— Deposit No. 38, dredged March 18, 19U4. Lat. 71° 22' S., long. Iff 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. nautiliforniis, 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, Expkl. Antarct. Fran<^aise commandee par le Dr Jean Charcot: 

 Moll., p. 5, pi. i. Hgs. 5, 6, 7 (Pari.s, 1906). 



Hah. — 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 Rissoidw. 



Rissoa deserta, Sm. 



liissoa deserta, K. A. Smith, Nat. Antarct. Kxped. : Nat. Hist., vol. ii. p. 9, pi. ii. fii,'. 1 

 (1907). 



Hah. — 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 (Onoha) jilostria, sp. n. (Plate, fig. 9). 



R. testa parvii, paullum inflata, .solidula, iiaruni riuiata, aiifractibu> 41, quorum apicales duo Ireves, 

 lumiduli, cioteris ventricosis, apud suturas impressis, arctissimu spiraliter teuuiliratis, apertura ovata, alba, 

 labro paullum etl'uso, baud multum iuorassato, fere contiuuo. 



Loug. 2, lat. 1'50 mm. 



//«&.— South Orkney Islands, Scotia Bay, 9-10 fathom.s. Station 325. 



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



(rOY. SOC. EDIN. TR.ANS,, vol.. XLVIIL, .349.) 



