174 Gatllff and Gabriel: 



Hah. — Off Wilson's Pioniontorv, Couiinonwealtli Trawler " Endea- 

 vour," one left valve. 



Ohx. — Our sintjle valve agrees in all particulars with specimens <^f 

 V. (lilerta var. e.rrehior. Verco. of which we possess a fine series, 

 kindly sent to us by the author. The description and figure of the 

 tertiary C. calva, Tate, sugpested to us a striking similarity, and 

 on critical examination, we were forced to the belief that this was 

 another instance of a siirvivor. With types of both shells existent, we 

 deemed it expedient to have a comparative examination, and submit- 

 ted to Dr. Yerco specimens of ('. mJiut, from Forsyth's. Grange 

 Burn, Victoria (of kalimnan age), with otir living representative, of 

 V. excelsior, from Wilson's Proujontory. Our contention is e\ndent, 

 as will be seen in the following reply, received 25.4.12: — "'I have 

 examined the type and co-types of C. calva, Tate : on his own tablet 

 are 15 shells, two showing the inner view, and 13 the outer. The 

 type specimen is the largest, and is quite indistinguishable from what 

 we have called here Cardita dihcia. Smith : its eccentric and radial 

 sculpture are exactly the same, and the ]nirt near the umbo has the 

 radial sculpture visible, except immediately round its apex. The 

 other examples on his tablet are smaller, and these have the eccentric 

 (concentric) grooves, well marked, in some instances to the ventral 

 margin ; but these are smaller shells — in larger ones this may 

 occupy half the surface of the shell, or more. This part is smooth, 

 and may show scarcel)'' any radial markings ; in fact, in one valve, 

 where at least 20 of the concentric markings can be counted, and 

 where they reach the ventral border, only 2 or 3 radial incisions 

 are visible in the anterior, and in the posterior part of the valve. 

 Is not this smooth part simply due to rubbing, and the wearing off of 

 the sculpture? This area is so variable in size, and so limited to the 

 prominent part of the shell, that this explanation suggests itself. I 

 am satisfied that Tate's C calva is my C'. ercehior, and unless there 

 is an omission in Suiith's description and figure, is not C. dihcta, 

 Smith. Tate's name is unfortunate, for the ' baldness ' (calva) is 

 probably accidental, and his type is barely bald at the extreme 

 apex." C. calva somewhat recalls C. dilecta. Smith, but is easily 

 distinguished, as Dr. Verco states, by its excentric concentric grooves, 

 which are not in the slightest degree indicated in the figure and de- 

 scription of r. dihcta (" Chall. Zool."). The distribution of C. calva 

 is interesting, as, with a specimen from the trawler " Endeavour,'' we 

 are able to extend its range to Oyster Bay, Tasmania. 



CARniTBLLA BXULATA, E. A. Smith. 



1885. Carditella exulata, E. A. Smith. Chall. Zool.. vol. xiii.. 

 p. 215, pi. 15, f. 6, Ga. 



