NASSA. 349 



1844 ; and he has given us some amusing particulars of 

 the fry. These behaved themselves like the fry of other 

 Gastropods^ skipping about and whirling round by means 

 of their ciliated lobes_, apparently in a state of pleasur- 

 able excitement; but it seems that the exercise was 

 compulsory^ or necessary to prevent the attacks of a 

 swarm of Infusoria^ which made short work of any tired 

 or feeble infant Nassa. The shell varies considerably 

 in size and in the length of the spire ; an adult speci- 

 men, from Mr. Clark^s collection, is not half an inch 

 long. 



Linne gave the Mediterranean as the only locality 

 known to him. The present species is the Buccinum 

 cancellatum &c. of Lister, B. vulgatum of Gmelin, and 

 probably the B. tessulatum of Olivi ; B. reticulatum of 

 the last-named author may be the next species. The 

 young appears to be the B. pullus of Pennant but not of 

 Linne. 



2. N. ni'tida^, Jeffreys. 



Body greyish, with a slight tinge of purple, and closely 

 speckled with fiake-white : pallkil tube cylindrical, very long, 

 slender, and flexible: tentacles flattened, tapering to a fine 

 point : eyes small, on stalks conjoined with the tentacles on 

 their outside ; these stalks are about half the length of the 

 tentacles, so that the eyes are placed about the middle of the 

 latter : foot broadly lanceolate, squarish and double-edged in 

 front, with small and pointed corners, blunt and wedge-shaped 

 behind ; tail forked and ridged : appendages rather short and 

 yellowish. 



Shell differing from N. reticulata in the following particu- 

 lars : — It is smaller, narrower, and remarkably glossy ; the ribs 

 are much fewer, viz. 10 to 12 on the body-whorl, 15 on 

 the next, 16 or 17 on the next, and 18 on the next whorl, 

 when they diminish in number upwards ; occasionally the ribs 

 are varicose ; the spiral striae or ridges are also less numerous. 



