GASTEROPODA. 87 



recent shell, which Mr. Jeffreys considers as Truncatella atomus, 'Phil. En. Moll. Sic.,' 

 vol. ii, p. 134, Tab. XXIV, fig. 5. There is a figure of the animal and shell by Mr. 

 Jeffreys in the 'Ann. and Mag. Nat. Hist./ January, 1859, p. 18, PI. Ill, fig- 16, 

 where it is described under the name of Euomphalns nitidissimus. 



Cecum trachea, Mont. Crag Moll., vol. i, p. 115, Tab. XX, fig. 5. 



— mammillatum, S. Wood. Crag Moll., vol. i, p. 116, Tab. XX, fig. 4. 



— glabrum, Mont. Crag Moll., vol. i, p. 117, Tab. XX, fig. 6. 



— incurvatum, Walker. Crag Moll., vol. i, p. 117, Tab. XX, fig. 7, a, b. 



The above four species were given by me in the ' Crag Mollusca,' but incurvatum only 

 provisionally, as being possibly the young of one of the other species. 



Dr. Philip Carpenter in his "Monograph on the Ccecida'" 'Proc. Zoo. Soc. 5 , 1858, 

 dissents from my determination of C. trachea, and regards the shell figured by me under that 

 name as a new form, to which he assigns the name of tumidum, rejecting the living species 

 trachea from the Crag category. 1 My species C. mammillatum he recognises, as well as 

 C. glabrum, Mont., while C. incurvatum he also thinks may be the young of one of the other 

 species. He also recognises among my specimens placed in the British Museum a new 

 form, which he names liratum ; and he makes new genera for the reception of all. 



As Dr. Carpenter has made the family of CoBcida a special object of study, I think 

 it desirable (though I do not fully agree with him) to give the Crag Ccecida according 

 to his views, which are thus : 



Carpenter's Names. Names in Crag Mollusca. 



Elephantulum liratum Not given. 



Anellum tumidum Cmcum trachea, vol. i, p. 115, Tab. XX, fig. 5. 



Fartulum mammillatum, .... (7. mammillatum, vol. i, p. 116, Tab. XX, fig. 4. 



Brochina glabra C. glabrum, vol. i, p. 117, Tab. XX, fig. 6. 



Young of mammillatum C. incurvatum, vol. i, p. 117, Tab. XX, fig. 7. 



Dr. P. Carpenter does not recognise any of these forms as living, with the exception 

 of glabra. Mr. Bell gives ('Ann. and Mag.,' May, 1S71) C. mammillatum from the Red 

 Crag of Walton Naze. 



1 In my Catalogue in ' Mag. of Nat. Hist.,' 1842, I placee a note of interrogation against C. trachea, 

 and pointed out that the recent shell is regularly annulated and smooth, and that my Crag shell differed 

 from it in having the annuli more irregular and rugose. 



