JMr. E. A. Sinitli on Mysclla. 235 



"P. Deshayesii, Rccluz " (H. & A. Adams), in Mylltta. 



P. tasmanica, Ten.- Woods in Mylilta. 



P. Stoivei, Ilutton in Mylitta. 



P. (j/emmata, Tate in Mylitta? 



P. mactroides, Hanley in Kellia. 



P. nuculoides^ Ilanlcy in Kellia. 



"P. Geoffroyi^ Payr, (Jeffreys) " ... in Kellia. 



P. paula, A. Adams in Tellimya. 



P. peculiarisj A. Adams in Tellimya. 



P. loivis, Carpenter in Tellimya. 



P. arcuata, A. Adams in Tellimya. 



P. triangularisj A. Adams in Tellimya. 



"P. C07??/K«c^a, Gould " (Tryon) .... inTellimya. 



"P. arcuata, Lamk." (Hinds) .... in Tellimya? 



P. striatissima, Sowerby in Montacata. 



P. sefosa, Jeffreys (non Dunker) ... in Montacuta. 



P. rugifera, Carpenter m Montacata? 



P. Guviingiiy A. Adams in Lepton. 



[b) On Mysella. 



This genus was created by Angas for a small Australian 

 bivalve and described in the Proc. Zool. Soc. 1877, p. 176. 

 The description he gives of the hinge is inaccurate in more 

 respects than one. In one valve, which I take to be the 

 left, he mentions " a single small, diverging, subcircular, 

 flattened cardinal tooth." This is posterior to tlie triangular 

 cartilage-pit beneath the umbo. It certainly cannot be called 

 " subcircular," for the upper side of it is almost straight and 

 the lower gently curved. In addition to this there is a second 

 but much smaller tooth on the anterior side of the cartilage- 

 pit, entirely overlooked by Mr. Angas. The right valve has 

 the hinge-margin on each side the umbo produced, for tiling 

 teeth as it were, which fit in above those of the opposite 

 valve. 



I have carefully studied the types of Mysella anomala, 

 Angas, and Mysella donaciformisj Angas, kindly presented 

 to the British Museum by that author, and I fail to discover 

 any reasons for separating them from the genus Tellimya. 

 The fact of the cartilage-pit being more visible and more 

 triangular than in the type of the genus, T. hidentata, is of 

 no importance, and merely what we might expect in larger 

 species like those. 



