179 

 ADDITIONS TO "BRITISH CONCHOLOGY. ' 



By T. T. MARSHALL. 



Part VII. 



[With tlie consent of tlie author, it is proposed to publish a Reprint of Part VIL 



of his work on " Additions to British Conchology," which was withdrawn 



from the pages of the Journal in 1902, and printed separately for private 



circulation. 



In accordance with the previous parts, the nomenclature followed is tliat of 



Jeftreys' "British Conchology,"except v\here altered on stated grounds. — En.]. 

 References to the previous parts are as follow : — 

 Additions to " British Conchology,"' Part i., Joiirn. of Conch., 1893, vol. vii., 



no. 8; Part II., 1894, nos. 10, il. 

 Alterations in "Britisli Conchology," Part lii., Joiirn. oj Conch., 1895, vol. viii., 



nos. I, 2. 

 Additions to " British Conchology," Part \v., /own. of Conch., 1897, vol. viii., 



nos. 10, II, 12; Part v., 1898, vol. ix., nos. 2, 3, 4 ; 1899, vol. ix., nos. 



5, 6, 7, 8 ; igoo, vol. ix., nos. 9, 10, 11 ; Part vi., 1901, vol. 10, no. 4 ; 



1902, vol. 10, nos. 6, 7. 

 Notes on the Britisli Species of j5//rr/;/?^w, Fnsns, etc., hum. of Malar. , 1902, 



vol. ix., no. 2. 

 Additions to "British Conchology," Part vir., Conclusion and Supplement, 



printed for private circulation, 1903. 



Marsenia perspicua L.— For the necessary change in this 

 generic name sea J^oi/rf/. of Conch., 1895, pp. 356. 



In estabhshing itself for breeding purposes among compound 

 ascidians, this species has the faculty, according to Giard, or 

 assuming the different colours and appearance of the particular 

 species of ascidian it may choose for a host, and Professor Herdman 

 has related a very striking case in point in the Conchologist for 1893 

 (no. 6, vol. ii.). Ciwyn Jeffreys and others have described and figured 

 the shell of the female as-the type. In the shell of tiie male, which 

 is rare, and known as var. teniaatlaia, the spire is much smaller and 

 flattened, and the aperture less curved at the outer margin. 



var. lata Jeffr. — In this variety, the upper edge projecting over 

 the aperture is much narrower than in the type, and the spire is 

 similar to that of the male, minute and depressed. It is surprising 

 that Jeffreys should have found this variety only " in deep water off 

 Unst," as it has occurred to me in various places, and will, I think, 

 be found generally diffused with the type, and in equally shallow 

 water. At any rate the following localities may be depended upon — 

 Sutherlandshire from haddocks (Baillie) ! Jersey, Penzance, Torbay, 

 Weymouth, Mayo, Sligo, Portrush, and Caldy Island. Jeffreys 

 has described the animal of this variety in his Appendix,' from which 



I Brit, Conch., vol. v., p. 216. 



