UNIVALVES. 



PLATE XLV. 



Genus. ARANEA. 



Character. Shell spiral; the mouth rounded; the spire short; the beak very 

 long ; the whole shell covered with irregular pointed spines ; no calcar or spur upon 

 the rostrum; number of the membranaceous divisions uncertain and irregular. 



Species. 



No. 1. Aranea denudata. Shell brown, with divisions painted in a variegated 

 pattern; mouth round, labiated, membranaceous, and projecting; spines 

 few, and thinly scattered up the body and beak. Found plentifully upon 

 the African coasts and seas. 



No. 2. Aranea tribulus. Shell brown, inclining to purple ; body tuberculated, 

 and beset with thick and strong spines, of these latter there are three rows, 

 one upon the back, and one on each side. It is found in various parts of 

 the Western Continent. 



No. 3. Aranea triremis. Shell slender, beautifully tapering, and much re- 

 sembling the triremis, or three-oared galley of the Ancients ; the spines are 

 elegantly sinuated, and tapering towards the extremities, forming at once a 

 delightful object, by the symmetry and union of its parts, and exhibiting the 

 most delicate taste in its form. It is found at Sumatra and other parts of 

 the East Indies. 



No. 4. Aranea tentacula. Shell pale brown, tuberculous ; the spines upon the 

 body short, those upon the back longer, and bent upwards like hooks ; mouth 

 round, and of a pale brown colour; the spire short and tuberculated. This 

 curious shell, which was hitherto undescribed, is from the Museum of Mr. 

 Latham. Native place unknown. 



REMARKS. 



The genus Aranea, so named from its resemblance to the spider, has characters so distinct 

 from the Murex, Buccinum, and Strombus, as to be easily distinguished at first sight. 

 Amongst these may be reckoned the spines, which are placed irregularly all over the shell, 

 and spring from the membranaceous divisions, which vary in number in the different species ; 

 the mouth also is closely inarginated by a projecting ridge, which almost shuts it out from the 

 beak, the latter being much longer in this than in any other shell. The spines may perhaps 

 serve as a guard or defence to the animal, to preserve it from danger, and also to facilitate its 

 rotatory motion at the bottom of the sea. The beauty and variety of this genus have always 

 strongly recommended it to the notice of Collectors, who think themselves very fortunate in 

 obtaining perfect specimens of it. 



