54 
IANTHINA. 
GENERIC CHARACTER: The shell inflated, conoidal* 
thin, transparent; aperture triangular ; columella straight 
passing beyond the base of the right lip. 
• I. COMMUNIS. Helix Ianthina. Tart. Lin. J. C* 
Flem. Brit. An., p. 326. Crouch’s Intro., pi. 16, fig. 
The species has been found on several parts of our north 
and south coast; I found it myself at St. Ives, and I p° 3 ' 
sess two or three specimens that came on shore not *® ( 
from my own residence. Their occurrence however, 
altogether casual, and depends on a combination of with 
and weather. The usual season is from July to November* 
when the wind is rougher long between west or south* 
under which circumstances several floating animals, aS 
Physalia, Velella, with the Ianthinae, are driven on « ul 
coast from the Atlantic, sometimes in considerable no* 11 ' 
bers. This shell, however, is so brittle, as scarcely to bear 
the touch of land ; and in consequence, vigilance must b® 
joined with good fortune, to obtain sound specimens. 
I. EXIGUA. Turton, Mag. Nat. Hist., vol. 7, p. 352. , 
Turton says. “In the small coves about the Land's-eU®’ 
in Cornwall, the Ianthina Fragilis (Communis) is occ*' 
sionally wafted, by a gentle south west wind, in prodigi° llS 
fleets; all alive, and born up upon the water by their cluster 3 
of tough bubble like vesicles. By the retreating waves, m° s 
of them are carried back into the ocean ; so that it requir e * 
a fortunate combination of tide, wind, and wave, to see the® 
in all their splendour. This most happens about the month 
of July and August. The fishermen’s wives call them ' 
horns, which supposes a prior knowledge of their appearan 0 ®* 
Among them are sometimes found a few of I. Exigua, wbif 1 
having been probably regarded as the young of I, Fragil |S ’ 
may have caused them to be overlooked.” “ In the conH 1 ' 
butions towards a History of Swansea, by L. W. Dill"'.' 1 ?' 
Esq.,” it is observed. “ 1624, July. Many thousand sh®‘j 
of Ianthina, of which some retained the animal alive ; al ? 
skeletons of the Medusa Velella and of Medusa Navic®* 9 ’ 
were thrown on the shores of Oxwich-bay ; the weather 
remarkably hot at the time. A few of these Ianthina, wb ,c 0 
had before at different times been washed up in the sa® 1 ^ 
bay, received front Dr. Leach his M.S. name of I. Rot® 1 ? 
data; and Mr. Jeffreys informs me, that among the multi 111 ^ 
which now covered the shore, he detected a few shell 3 
1. Mediterranea mixed with them.” 
MA CEOS TOM I A NA. 
The shell earshaped, aperture much dilated, margin 3 
united, no columella or operculum. 
