TELLINOMORPHA. 431 



have an entire pallial line, and one species, Clisenomya juanida, has not an 

 edentulous hinge ; for he says, " J'ai en outre pu observer dans I'impression de la 

 charniere de la G. jticunda, une petite fossette produite par la presence d'une dent 

 tres pen developpee et difficile a constat er." 



Certain species included under Clisenomya by de Koninck belong to a group of 

 Sangidnolifes, of which S. argnfits may be considered as a type, — for example, S. 

 Walciodorensis. I am of opinion that the Chaenomya juciinda of de Koninck really 

 belongs to that author's genus TeUinomovplia, with which it agrees in every 

 important character; and, on de Koninck's own showing, possesses the hinge which 

 lie considers as characteristic of that genus. 



TellinoDiorpha was erected as a genus by de Koninck to receive a single valve 

 from the Upper Carboniferous beds of Belgium, but the exact locality is not stated 

 in the text. Fortunately the hinge was exposed in this example, a right valve ; 

 and I am glad to be able to record the occurrence of the same species (T. cunei- 

 formis) in the uppermost beds of the mass of limestone at Castleton, Derbyshire, 

 and Hill Bolton, Yorkshire. 



British shells show that the genus had the surface of the valve covered by 

 radiating rows of small tubercles, a character, however, possessed b}^ other Car- 

 boniferous genera, notably Edmondia, Sanguinolites, and Allorisma. From the 

 tirst of these Tellinomorpha differs so essentially that it is unnecessary to discuss 

 the matter; but it has a very close affinity to Sanguinolites, from which it differs 

 in the possession of a denticulate hinge, and the absence of any approach to an 

 oblique ridge, even in the umbonal region. The escutcheon, too, differs in being 

 deeper and more concave in section, and not extending so far backwards as it 

 does in Sanguinolites, and not having the erect dorsal margin of that genus. 

 Tellinomorpha is not so transverse, has not the simple ribs and sulci, or the long- 

 escutcheon of Allorisma. 



The name TelUnomorjoha is a very unfortunate one, for the shells in question 

 have no affinity whatever with Tellina either in the general character of the valve 

 or in the structure of the hinge. It is impossible to conceive on what ground de 

 Koninck makes the following statement: — " C'est la premiere espece carbonifere 

 qu'avec une forte presomption d'exactitude on'peut introduire dans la famille des 

 Tellinidge; la structure de la charniere et la forme generale de la valve sont tres 

 semblables a celles de certaines especes vivantes appartenant acette famille." Tlie 

 name is quite as unfortunate, indeed, as TeUinomy a, which has the multidenticulate 

 hinge of the Nuculidse. 



TellinomoTplia more closely resembles several Jui'assic genera of Lamellibranchs 

 originally included under the Myacites of Schlotheim, but this fact has been 

 discussed above, p. 419. 



