WENTLETRAPS. 193 
upon that of their nidus) appears, like the larve of 
the ichneumon tribes among insects, to avoid the 
vital parts; for in no instance did Mr. Cuming find 
it imbedded anywhere save in the rays, though 
some of the individuals had penetrated at their 
base, and very near the disc. When extracted, the 
older shells have the appearance of a milky-clouded 
glass bubble: the younger shells Mr. Broderip 
found of an unclouded transparency. 
FAMILY SCALARIADA, 
(Wentletraps.) 
Though very limited in numbers, this family is 
interesting to the conchologist as containing some 
species of singular form and remarkable beauty, 
one of which was formerly valued so highly as to 
command enormous prices, and to have acquired 
the name of the Precious Wentletrap. “ In this 
family a spiral shell with an entire aperture is 
combined with an animal whose head is not pro- 
duced into a muzzle, but furnished with a retractile 
trunk. The sexes are distinctly separated. The 
eyes are immersed at the external bases of subulate 
(awl-shaped) tentacles.” The dentition of the 
ribbon-like tongue is very peculiar; there is no 
central tooth differmg from the rest, but all are 
alike, arranged in transverse rows, ‘and forming 
simple claw-like hooks. The animals are probably 
predaceous like the Whelks, &c. Most of the 
species, which amount to nearly a hundred, inhabit 
the seas of warm climates, though a few are found 
on our own shores. 
O 
