412 Mr. W, II. Benson on Ianthina, Bolten. 



bloom devoid of lustre. Of the former, three are pale externally, 

 the violet tinge being more vivid within the aperture near the 

 outer lip ; the fourth is altogether of a violet tint, more saturated 

 within the aperture. Of the two shells with a dull surface, one 

 is suffused with violet, the other is paler at the upper part. My 

 largest specimen is 18 mill, in length by 11 in breadth. Others 

 were procured of a greater size. Specimens stated to be from 

 the coast of Portugal exhibit a bluer tint than the rosy violet of 

 the southern shell. 



/. caruleata, Reeve, and var. 



In colour this shell was found to vary from that of /. caruleata, 

 Reeve, to that of /. yrandis of the same author, and in form from 

 I. caruleata in the depressed type, through I. communis, R. 

 (which, according to Morch, is a variety of /. bicolor, Costa), to- 

 wards /. grandis, the perfect form and full size of which Morch 

 affirms that 2. bicolor attains occasionally. Of seven specimens, 

 taken chiefly in my casting net, I retain five, the largest of which 

 is 29 mill, in height and 33 mill, in diameter. In my journal, 

 under date 2nd Dec. 1834, in 32° 26' S. lat. and 82° 21' E. long., 

 I noted that I had missed some very large specimens at which 

 I had thrown my net. 



Morch places I. bicolor (as/. Costa, Morch) and /. caruleata, R., 

 in the viviparous subgenus lodes, Leach, while he includes 7. gran 

 dis, R.,in the oviparous subgenus Achates, The float of my species 

 (under whatever name it may be retained) had a plane surface, 

 and one side was thicker than the opposite edge. It was com- 

 posed of large transverse bubbles. None of the specimens had 

 egg-cells attached; but numerous large floats procured with 

 them, and which, almost beyond question, belonged to the same 

 species, were found bearing egg-cells, as noted in my journal on 

 the 2nd and 3rd of December. The shells were taken daily, 

 from the 1st to the 5th of that month ; and as the Ianthina 

 which accompanied them belonged to a little variety of /. pallida, 

 and to /. exigua, the small size of those shells and the very dif- 

 ferent formation of their floats precluded the assignment of the 

 large egg-bearing floats to those species. More shell-less floats 

 were observed than those which bore shells. 



The animal was dark blue, with the exception of the whitish 

 tentacula, and it gave out a purple fluid which stained the nets 

 with a greenish colour. The white basal band in the specimens 

 which resemble /. cceruleata gives place in one conoid specimen 

 to a pinkish-violet band ; and in others the whole base is of a 

 uniform deep-violet tint, which gradually fades into opake white 

 towards the summit of the spire. The sculpture is more or less 

 rough in different individuals. The right lip is rather deeply 



