140 SUPPLEMENT TO THE CRAG MOLLUSCA. 
various acknowledged species of this variable genus might be so selected as all to run 
into one another and the whole of such species accordingly merged in one. In a genus 
such as this, wherein the specific forms thus graduate into one another, and which, 
moreover, goes back far into the Mezozoic formations with but little departure from the 
living types, a more arbitrary line of specific division should be allowed than im the case 
of species of less variable genera. 
Astarte Forsesit, S. Wood. Crag Moll., vol. u, p. 192, Tab. XVII, fig. 12 a, 6 
(as 4. parva). 
Localities. Cor. Crag passim. 
When describing this shell I was not aware that the name of parva had been given 
to another species in this genus; but I find that a fossil, which is quite distinct, has 
been so called by Dr. Lea (‘ Contrib. to Geol.,’ p. 63, pl. 2, fig. 37), and as this is of 
prior date (1833), my name, of course, must be suppressed. 
In a catalogue of the Mediterranean Mollusca by Mr. Jeffreys, published in the 
‘Ann. and Mag. Nat. Hist.,’ July, 1870, is the name Astfarte parva, S. Wood; and that 
gentleman there says, “ This may possibly be 4. pusilla of Forbes ; the inside margin is 
notched in my specimens ;” and in the list by the same gentleman accompanying Mr. 
Prestwich’s Cor. Crag paper this identification is imserted without any qualification. 
I have endeavoured to find out the type-specimens of Forbes’ species, but unsuccessfully. 
It is, however, described by Forbes as “ concentricé striata, margine interno denticulato ;” 
but as the markings on my shell are eccentric instead of concentric, and the margin free 
from denticulations, no greater discordance, so far as description goes, could weil occur. 
In general, where the /wd/-grown shell of Astarte has a denticulated margin, the young 
has this margin smooth, and as I have now before me one hundred specimens of this 
Crag species, not one of which has a denticulated margin, I can hardly suppose them 
all to be immature shells; I therefore cannot with any propriety refer the Crag shell to 
pusilla. Jt much resembles an Oligocene fossil named and described by Dr. Speyer as 
Goodallia Kéneni (‘ Die. Ober. Oligoc. Test. Detmold,’ tab. iv, fig. 6, 1866), which is 
ornamented with oblique ridges and has a smooth margin, but, judging from the represen- 
tation, it is not a satisfactory identification; therefore, until specimens can be compared, 
and as the name parva must be abandoned, I have assigned to my shell the name 
Forbesi. : 
The late Mr. McAndrew gave me some specimens of a small Astarte which he 
obtained in the living state off the Canaries, that much resembles the Cor. Crag shell 
called 4. parvula; but I think the recent shell specifically different; it is rather less 
oblique, the lateral denticles of the recent shell are shorter, and the ventral margin is 
denticulated. I have also a fossil specimen from Cannes, which is more shaped like 
Mr. McAndrew’s shell, but it has a smooth ventral margin. The following from the 
Upper Tertiaries of East Anglia I consider as distinct species : 
