ODOSTOMIA. 



155 



lip more or less distinct on the npper part of the pilhir, accord- 

 ing to the degree of maturity of the specimen, in other respects 

 Kke 0. interstincta, but not so straight on the lower part as in 

 that shell, and terminating in an obtuse angle : umhilicus con- 

 sisting of a more conspicuous chink than in the last-named 

 species : tooth very short, blunt and obscure, being seated far 

 within the pillar : operculum as in 0. intersthicta ; the inner side 

 is slightly notched to receive the tooth. L. 0*125. B. 0-05. 



Habitat : Equally distributed with the last species, 

 and inhabiting the same zones. Fossil : Dalmuir 

 (Robertson and Crosskey) ; glacial and post-glacial 

 shell-banks in Norway, the former at 400-460 feet, and 

 the latter at 50-100 feet (Sars) . Recent : Norway, as 

 far north as Oxfjord in Finmark, 10-40 f. (Sars) ; Swe- 

 den, 10-17 f. (Loven and Malm) ; Cattegat (mus. Co- 

 penh.) ; Loire-Inferieure, among Corallina officinalis 

 (Cailliaud) ; Rochelle (D'Orbigny pere) ; off Gibraltar, 

 8-30 f. (M^Andrew) . 



Specimens in my collection from Shetland are covered 

 with Discorhina glohularis. Some are distorted in the 

 same way as those which I noticed when treating of 0. 

 interstincta. The striae which encircle the base of the 

 shell distinguish the present from any other species. 



It is the Voluta pellucida of Dillwyn. A worn speci- 

 men was described by Macgillivray as 0. plicata. 



25. O. exi'mia*, Jeffreys. 



Rissoa eximia, Jeffr. in Ann. & Mag. N. H. new ser. iv. p. 299. Chem- 

 nitzia cximia, F. & H. app. p. 278, pi. xc. f. 1 (as i?. cximia). 



Shell oblong, rather solid, semitransparent and glossy : 

 sculpture, fine curved longitudinal ribs, which do not reach the 

 base ; 15 or 16 of them may be counted on the last whorl ; 

 these (or more frequently their interstices) are crossed by 3 

 spiral stria) or finer ribs, which traverse the middle of this 

 whorl, and give a partially cancellated appearance to the shell ; 

 the next whorl has 2 or 3 similar striae near the base, the 



* Uncommon. 



