MOLLUSCA OF INDIA. 197 
pale cinnabar-red ; eyes small, jet-black, situated on tubercles, which 
are on the head, and joined to the outer base of the tentacula. The 
foot is greyish white, the sole pale, the muzzle a pale reddish buff- 
colour. 
“The operculum, which is carried centrally on the hinder part of 
the foot, about midway between the shell and the tail, is capable of 
being withdrawn beyond the internal opening of the sutural tube, 
although ordinarily closing the aperture. 
“There is no organ to be seen corresponding with the internal 
sutural tube, the animal in this respect exhibiting a similarity to 
that of Pterocyclos, which, as described by me in 1836, possesses no 
soft parts calculated to fill the anomalous portions of the shell near 
the aperture. 
«“Operculum very thin, horny, concave externally, consisting of 
62 concave volutions with a varnished surface. 
«For the single living specimen of this shell I am indebted to 
Captain R. H. Sankey, by whom it was taken in January. It 
remained closed in its shell until the 27th of June, when it began to 
yield slowly to the means employed to revive it, finally moving 
about and creeping freely under an inverted glass.” 
In 1863 Mr. Blanford had an opportunity afforded him of looking 
more closely at the animal preserved in spirit, and Mr. Benson’s 
conclusions regarding the absence of any process analogous to the 
tube were found to he erroneous. 
In Mr. Blanford’s paper “On the Animals of Raphaulus, Spira- 
culum, and other Tube-bearing Cyclostomacea,” Annals & Mag. Nat. 
Hist., July 1863, this subject is well discussed; and as our knowledge 
of the subject has not been increased since that time, I shall extract 
it in full:— 
“No one can have examined carefully a collection of the operculated 
land-shells of India and South-eastern Asia without remarking the 
peculiar shelly processes of the peristome or suture which charac- 
terize several of the genera. Two principal forms of these processes 
may be distinguished, viz. (1) sutural tubes, either open at both ends 
or closed at one extremity, as in the genera Raphaulus, Spiraculum, 
Opisthoporus, Alyccus, Ke., or, (2) incisions in the peristome— 
simple, as in Pupina, Registoma, &e., or accompanied by expansions 
of the outer lip, as in Pterocyclos and Rhiostoma. So far as I am 
aware, uo soft parts have hitherto been observed in the animals of 
any of the above genera, corresponding to the peculiarities of their 
shelly coverings. During the past two or three years, I have ex- 
amined carefully the animals of species belonging to the majority of 
the above-named forms; and in two instances I have ascertained the 
existence of an organization to which the processes of the shell! are 
adapted, these two cases being in the genera Raphaulus and Spira- 
culum, which, although by no means nearly allied, agree in possessing 
a sutural tube opening both internally and externally. 
«By the kindness of Baron F. v. Richthofen, I had, some time 
since, an opportunity of examining the animals of several specimens 
of the rare Raphaulus chrysalis, Pfr., from Moulmein in Burma. 
PART V. s 
