OF SOUTHERN INDIA. 389 
The HaLIOTID# are principally inhabitants of the eastern seas, West Africa, the Indian, 
Australian and Philippine Archipelago. Only very few are found in the Mediterranean and in 
the Arctic seas. 
Fossil species of Haliotis are extremely rare; there are only very few known from tertiary 
deposits, and one from the cretaceous. I can only mention the doubtful Haliotis* antiqua, Binkhorst 
(Mon. Gast. et Ceph. de la eraie de Limbourg, 1861, p. 81, pl. 57%, fig. 4), from the Maestricht 
chalk. The specimen is a small and rather imperfect one, subcircular, the whorls increasing: gra- 
dually ; the spire is raised, the perforations are surrounded with a somewhat raised, rounded margin. 
It is usual to find the genus Cirrus, Sow., quoted in the neighbourhood of 
Haliotis or of Plewrotomaria, and it may be not out of place to give here a short 
notice of the same. The name Cirrus was introduced by Sowerby in 1818 (Min. 
Conch., II, p. 98, pl. 141), for three paleeozoic species, C. acutus, nodosus, and 
plicatus. All three are turbinate shells, with roundish whorls and a large umbi- 
licus. The first and third I am unable to distinguish from Straparolus, except 
by their having a somewhat more elevated spire. Cirrus nodosus has some 
tubercles on the upper portion of the whorls, but appears to have been only 
determined from a cast, so that these tubercles represent the remnants of rather 
prolonged spines on the surface of the shell. It is on account of these spines 
that d’Orbigny (Prod. I, p. 68) retained the name Cirrus. Subsequently in his 
Pal. franc. terr. jur. II, p. 376, etc.), the same author described two very 
characteristic species from the liassic beds of Fontaine- -Etoupe-four, Cirrust Nor- 
manianus and ©. calcar. Both these species are more discoidal than Sowerby’s 
C. nodosus, and have the spines very distinct ; of these a few, being placed near the 
aperture, are stated to be open at their terminations. 
Now, looking at the interstices between the base of each two spines, we often 
see the shell somewhat raised, but never forming a distinct band and, therefore, the 
genus cannot be placed in the Pzzvroromarripa, as suggested by several concho- 
logists who have merely taken notice of the general form of the shell. Com- 
paring, on the other hand, the tubes of Cirrus with the occasionally tube- 
like perforations and their interspaces of Haliotis they must be admitted to be 
very similarly formed, especially since these perforations correspond to each other 
in their position with respect to the form of the whorls. The only important 
matter to be ascertained is whether the shell of Cirrus has an internal pearly 
layer or not. If it has one, the genus could form a distinct sub-family in the 
Hatrorrp#, though I must say I rather doubt the probability of the correctness of 
this classification. If it be, however, not pearly within, the genus has (and this 
is more probably correct) to be placed in the Sozaripzx, next to Straparolus. 
The row of tubes in Cirrus is in every way so thoroughly analogous in its 
formation to the upper tuberculated keels of some characteristic Straparoli, that it 
is most difficult to draw a line of distinction between them. 
The only other two genera which I could mention as being related to Cirrus 
are Onustus and Guilfordia, the last of which is internally pearly; the former not, 
* Binkhorst writes Haleotis. 
+ It is not evidént for what reason d’Orbigny has here changed the generic name into Cirrhus. 
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aC 
