424 



near the mouth, will not justify specific separation merely on geo- 

 graphical grounds. 



12. Cecum elongatum, Cpr. 



C. (Anellum) t. elongata, tereti ; primum Icevi, dein annulis ro- 

 tundatis parum extantibus instructa, interstitiis minimis ; 

 septo ungulato, apice parum elevato, subobtuso ; margine late- 

 rali subrecto : operculo ? . . . 



Test. jun. long. -06, lat. -008— '017. 



Test, adult, long. -103. lat. -015— -023. 



? Var. semilseve. T. hue et illuc annulata ; hue et illuc Icevi. 

 Long. -112, lat. '025— -028. 

 Hab. Mazatlan, very rare. Mus. Brit. &c. 

 Maz. Cat. p. 319. 



About a score of specimens were found, including the ? variety, 

 which may be distinct. The shape approaches Elephantulum. 



13. Cecum subimpressum, Cpr. 



C. (Anellum) t. elongata, solidiore ; annulis creberrimis, rotun- 

 datis, haud extantibus, interstitiis subimpressis ; septo mucro- 

 nato ; margine laterali vix concavo ; mucrone parvo, obtuso, ad 

 dorsum sito : operculo concavo, linea elevata suturam defi- 

 niente. 



Test. jun. long. -058, lat. -008— -016. 



Test, adult, long. -115, lat. -017— '03. 



Hab. Mazatlan, very rare. Mus. Brit. 



Maz. Cat. p. 320. 



This species differs from C. elongatum in the narrow mucro. 

 About a dozen specimens were found. 



i, St)m||. 

 gat a, sola 



14. Caecum pulchellum, 



C. (Anellum) t. satis elongata, solidiore, pallide fusca ; t. ado- 

 lescente gracili, annulis paucis distantioribus ; t. adulta an- 

 nulis circiter xxv. validis, rolundatis, interstitiis plus minusve 

 cequantibus ; septo 1 mamillato, haud extante ; margine laterali 

 parum convexo : operculo concavo, anfr. circiter viii. 



Long. -1, lat. -025. 



Hab. New Bedford Harbour, U.S., adhering to groups oiVermeti 

 in laminarian zone. 



Stimpson in Proc. Bost. Soc. N. H. Oct. 1851 ; Shells N. Eng. 

 p. 3G. pi. 2. f. 3. 



The above description of the plug, which was not noticed by 

 Stimpson, is supplied from the figure. If correct, it is the only 

 Anellum known with a purely mamillate plug. 



h). C.ecum trachea, Mont, (diagn. auct.) 



('. (Anellum) t. haud parva, solidiore, rufo-fusca, haud opaca ; 

 t. juniore Icevi ; adolescente tereti; adulta cylindrica, annuli* 



