MALACOZOA. GASTEROPODA. PECTINIBRANCHIATA. 173 



5. Pleurotoma reticuldtum. Reticulated Pleurotoma. 



Shell oblongo-fusiform, thin ; with the spire tapering to a 

 rather obtuse point, and somewhat convex in outline ; the 

 whorls slightly angulate at the upper part, giving the spire 

 somewhat of a scalar appearance, but with the space between 

 the angle and the suture convex and sloping ; the last whorl 

 of rather less breadth than the length of the spire ; the suture 

 distinct ; the whorls with numerous transverse narrow ribs, on 

 the last dividing into several raised lines, and on all reticulated 

 with longitudinal raised lines; the aperture oblong, narrow, 

 deeply sinuate at the suture, with the outer lip thin, the canal 

 very short, the inner lip with a rather thick, smooth layer ; the 

 colour dull white. Length half an inch, breadth a third of 

 the length. 



A single specimen sent by Mr. Alexander Murray, who 

 found it at Slains, in November, 1842. 



Pleurotoma reticulatum. Brown, Illustr. PI. 38. f. 43, 44. 



GENUS 3. ROSTELLARIA. 



Animal with the body elongated, spiral ; the head 

 with two conical tentacula, bearing the eyes on a pro- 

 minence at their base externally ; the mouth at the end 

 of a long cylindrical annulated proboscis, and a filiform 

 tongue ; mantle, forming a thin-edged flap over the 

 branchial cavity, and on the left side an elongated open 

 canal, which emerges by a groove in the shell ; branchiae 

 two, unequal, pectinate ; foot large, generally broad ; a 

 horny operculum. 



Shell more or less turrite or fusiform, spiral ; its 

 aperture oblong, with a prolonged canal for the respi- 

 ratory tube, and the outer lip much expanded in old in- 

 dividuals, entire, dentate, or digitate. 



1. Rostelldria Pes-pelecdni. Pelican' s-foot Rostellaria. 



Shell turrite, with the spire tapering to a point, the suture 

 distinct, the whorls ten, convex, with a medial series of oblique 

 compressed obtuse nodules, and fine spiral striae, the last 

 whorl with two additional nodulose bands, the lower smaller 

 and approximated ; the aperture oblique, oblong, with the 

 outer lip extremely dilated, angulate, very thick, sinuated 

 r2 



