CERITHIUM. 261 



loupe as the habitat of his C. lima, a name which many 

 subsequent writers have adopted for the European 

 species, which may be his C. ferrugineum. C. afrum of 

 Danilo and Sandri appears to be nothing more than a 

 small and dark-coloured sort of this most variable shell. 

 I have the same from the Adriatic ; Brusina erroneously 

 referred it to the genus Cerithiopsis. Forbes and Hanley 

 say that '' the specific name scabrum was undoubtedly 

 prior to that of reticulatumP My copies of Da Costa^s 

 and Olivias publications show, however, that reticulatum 

 is foui'teen years older than scabrum. 



3. C. perver'sum^, Linne. 



Trochts perversus, Linn. S. N. p. 1231. C. adversiim, R & H, p. 195, 

 pi. xci. f. 5, 6. 



Body slender : Tiead broad, short ; proboscis capable of being 

 concealed ? (recondenda ?) : mentum distinct, in front somewhat 

 detached, and actively vibrating : tentacles long, cyhndrical, 

 slender, somewhat club-shaped at the top, separated at the 

 base, connected by a flexuous veil : eyes on very short stalks 

 or processes, at the base of the tentacles : opercular lobe simple. 

 (Loven.) 



Shell sinistrorsal, forming a more or less elongated pyramid, 

 with a narrow and somewhat contracted base, solid, opaque, 

 rather glossy: sculpture, rows or bands of small and close-set 

 tubercles (about 25 in the lowest row), produced by the 

 mutual decussation of spiral and longitudinal ribs ; of these 

 rows there are usually 3, sometimes 4, on the body -whorl above 

 the periphery ; the tubercles on that whorl are generally oblong 

 with the greater axis in the direction of the spire, the others 

 being granular or bead-like ; each of the next 5 or 6 whorls 

 has 3 rows, the next 5 or 6 whorls have 2 rows each, the 

 following 3 or 4 whorls are not tuberculated, but exhibit 

 very minute and numerous longitudinal striae, which are 

 encircled in the middle by a delicate spiral thread, in such 

 a manner as to make the primary whorls appear keeled or 

 angulated ; the nucleus or top whorl is smooth and glossy ; 

 the middle row (when there ai-e 3) is frequently smaller 



* Turned the wrong way. 



