12 CRETACEOUS PELECYPODA 



In Kiiph. «?'e«rt?'i»s no shell is kno"n'n to exist, but Desliayes notices, as a second 

 species of the same genus, the Sept. Iledttei'ranea of Matheron, which has subse- 

 quently beea stated to be identical with Teredo norveyica. Of the first species the 

 same author says that it only differs from Teredo by living in sand and not in Avood. 

 There are two small valves present and two palettes as in Teredo. The question as 

 to the real character of ^S*. Mediterranea and Guettard's genus Kiiphus appears, 

 therefore, still unsettled. Desliayes in his last edition of the Pains fossils (1860, 

 vol. i, p. 107,) gives a list of the genera of the Tkolavib/e, but on this occasion he 

 omits the name Septaria altogether, which tends to prove that he considers it to be 

 identical with Teredo. 



Wright in his recent paper on the Teeebidm (Trans. Lin. Soc, Lond., vol. xxv, 

 p. 563), quotes the authority of Sir E. Home in support of the statement, that 

 in the tube of Knplms arenarhis " both valves and palettes, have been discovered." 

 The palettes of Kup)Jms arenarius Dr. Wright found to be very similarly fonned 

 to those of a species which he obtained from Singapore, and which he described 

 imder the name <di Ktiplms? Mannil ; it has a shell like Teredo. A very similar, or 

 probably the same, species as the last also occurs about Calcutta in the Gangetic 

 Delta, and I can confirm Dr. Wright's account in this respect. Besides this 

 I also obtained here perfect specimens of one or two species of Nausitoria, a 

 Xijlotrya, and I hojie also to procure good specimens of Calohates. Some interesting 

 points as regards the anatomy of these animals I trust to be able to publish 

 shortly. 



A question, which it is desirable should be settled as regards the species 

 Eiiphns arenarms, is, whether it really possesses valves similar to those of Teredo, 

 or whether it has none. Judging from the species described by Wright as Kuph.? 

 Ilannii, Sii'E. Home's statement regarding K. arenarius is, I believe, very probably 

 correct, and in such a case the necessity for a special sub-family ceases. 



The fossil genus Teredina will be noticed among the peoladin^ ; thus we shall 



retain in the sub-family teredinin^ only those forms which are generally known 



under the ancient name of Teredo. Subsequent discoveries seem, however, to 



make a sub-division of this old generic group very desirable, and, as already 



noticed, the form and structure of the palettes, or styles, has been suggested as 



the base of distinction. Objections have been raised against this, stating that no 



generic importance can be attached to these palettes. It is really difiicult to form a 



very coiTcct idea on this point. Por my own part I do not consider it satisfactorj% 



but it is certain that the known species can be, - to some extent at least,- grouped 



according to the form of their palettes, and, whether we call these groups genera or 



sub-genera, is, as the greater number of naturalists Avill admit, of minor importance. 



In cases like this the most convenient mode ought to be adopted. The palettes 



protect the siphons, Avliich are a very important part in the organisation of the animal, 



and any changes made in the latter will probably produce a difference in the former ; 



thus they are in close connection with each other. The valves in the TESEsiMx.ii are 



always of the same kind, and, as already noticed, sometimes not to be distinguished 



