MALACOZOA. GASTEROPODA. 



345 



liforrn appendages ; mantle very large, widely open in 

 front, and also communicating by a fissure with a cor- 

 responding aperture in the apex of the shell ; two large 

 equal, pectinated branchise ; intestinal aperture at the 

 extremity of a small tube opening into the respiratory 

 cavity. 



Shell oblong, conical, destitute of spire, having the 

 base oblong, with the margin continuous, the summit 

 truncate and perforated by an oblong aperture. 



1 . Fissurella Nubecula. Red-rayed Fissurella. 



Shell oblong, conical, little elevated, with about fif- 

 teen broad ribs, alternating with smaller, and somewhat 

 reticulated with inconspicuous concentric lines ; the 

 colour brownish-red rayed with reddish- white. 



Shell ovato-oblong, somewhat translucent ; with the sides 

 of the aperture or base nearly straight, its margin plain, the 

 posterior extremity narrower ; conical, little elevated, with 

 the apex a little behind the centre, obliquely truncate, with 

 an elliptical aperture, having the margin smooth ; the exte- 

 rior rayed with alternate dark brownish-red and white bands, 

 and raised into fifteen thick ribs, with smaller intervening 

 ridges, and concentric elevated lines, decussating the rays, but 

 not very conspicuous ; the interior smooth, purplish-white, 

 and with a ring of pale-reddish purple around the thick 

 whitish marginal rim. Length three-twelfths and a-half, 

 breadth a little less than two-twelfths, height a twelfth and 

 a-fourth. 



The above description from an individual found by Mr. 

 Alex. Beaton, in February, 1843, adhering to an Actinia 

 from off Aberdeen. 



"Patella Nubecula. Lister. Conch. PI. 59." Patella Nube- 

 cula. Turt. Conch. Diet. 142. Fissurella Nubecula. Bisso. Eur. 

 Merid. iv. 257. 



Natica monilifera. P. 51, 125. 



A great number of fine specimens of this animal 

 having been cast alive on the beach near Aberdeen, in 



