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 reticulatum." My copies of Da Costa's 

 and Olivias publications show, however, that reticulatum 

 is fourteen years older than scabrum. 



3. C. pervek/sum*, Linne. 



Trochus perversus, Linn. S. N. p. 1231. C. adversum, F. & H. p. 195, 

 pi. xci. f. 5, 6. 



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

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

 detached, and actively vibrating : tentacles long, cylindrical, 

 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, oj)aque, 

 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 are 3) is frequently smaller 



* Turned the wrong way. 



