NUCULA. 177 



longer be referred to this genus ; two belong to Nuculana, and of the three which 

 are correctly referred to Nucula, N. tumida is synonymous with N. gibbosa, 

 Fleming. M'Coy invented eleven species of Nucula, four of which do not belong 

 to the family ; and the rest, with one exception, N. oblong a, should without doubt 

 be placed in the genus Nuculana. 



Of the three species described by Sowerby in the Appendix to the ' Geology of 

 Coalbrookdale ' (1840), only one, N. sequalis, belongs to that genus; one other, 

 N. acuta, should be referred to Nuculana; and N. accipiens is evidently the young 

 of the shell described in that Appendix as JJnio TJrei. 



The shell figured as Gtenodonta, sp. ? by Salter, pi. i, fig. 3, in the Memoir on 

 ' The Country round Oldham ' should more properly be referred to Nuculana 

 Isevirostrum, Portlock. 



Salter instituted the genus Ctenodonta.ior those nuculiform shells which did not 

 possess a cartilage-pit between the anterior and posterior series of teeth, and had 

 an external ligament. He was under the impression that some of the Carbo- 

 niferous nuculiform shells (belonging to both Nucida and Nucidana) possessed 

 these characters, but this has been pointed out by Goodchild, Whidborne, and 

 others to be a mistake. Tellinomya of Hall is doubtless a synonym of Gtenodonta ; 

 but there is some little question of the priority of these names, which is briefly 

 stated thus : 



In 1847 Hall invented the name Tellinomya, and founded the description on 

 the species Tellinomya nasuta. 



Salter, in the 'Report of the Geological Survey of Canada,' 1851, dec. 1, p. 34, 

 pi. viii, figs. 1 and 2, proposed the genus Gtenodonta for the same species, on the 

 grounds that the term Tellinomya gave an altogether wrong view of the genus, 

 which belonged to the Nucididse. Unfortunately this reason is untenable. 

 Further, Brown had in 1827, in his work on recent ' Conchology,' invented the 

 term " Tellimya " for a recent genus of shells, which he considered had characters 

 of the genera Tellina and Mya. This is now referred by Fischer to Montacuta, 

 Turton. 



In 1846 Agassiz, seeing the orthography of the word " Tellimya " was 

 wrong, altered it to " Tellinomya." 



Two questions arise : 1st. Does the use of the word " Tellimya " preclude the use 

 of " Tellinomya'' for a totally different genus ? 2nd. Is it admissible to amend the 

 name " Tellimya" for orthographic reasons to " Tellinomya " ? 



Oehlert sums up (' Bull. Soc. geol. France,' ser. 3, vol. xvi, p. 653) in favour of 

 the retention of Gtenodonta, Salter, and considers Tellinomya, Hall, preoccupied by 

 Tellimya, Brown, though he does not seem to have been aware of the alteration of 

 " Tellimya" to " Tellinomya " by Agassiz. 



23 



