236 Mr. E. A. Smith on a new Species o/Mylitta. 



(c) Desceiption of a new Species of Mylitta. 



Mylitta auriculata, sp. n. (PI. XIII. A. figs. A, B, C.) 



Testa subcircularis, gequilateralis, supcrne utrinque umbones auricu- 

 lata, aiiriciilis teiiuibus, excurvatis, alba, mcdiocriter convexa ; 

 valvar crassa3, umbones versus sublaeves, deinde usque ad mar- 

 ginem radiatim fortiter costata), costis subacutis, promineutibus, 

 inter costas concentrice rugose striatoe, vel teuuissime biraellatie : 

 umbones parvi, acuti, autrorsum curvati; dens cardinalis unicus 

 valvar dextnc parvus, conicus, laterales duo utrin(]uc sed propc 

 umbonem validi, divcrgentes ; dens cardinalis valvar sinistrae 

 bifurcatus, lateralis unicus utrinque prominens, crassus ; fossa 

 ligamenti profunda, mediaiia, subtriaugularis, pone dentera car- 

 dinalcm sita : pagina interna radiatim sulcata, ad marginem vuldo 

 crcnulata, ad extromitates costarum brcvitcr incisa ; cicatrices 

 parvsD, subrotunda3, et linea pallii simplex. 



Longit. 8 millim., alt, 6|, diam. 3j. 



Ilab. Tasmania. 



In solidity, colour, and dentition this very remarkable shell 

 agrees exactly with the type of Mylitta, but dilfers from it in 

 having the su])erficial costm arranged in a radiating instead 

 of a divaricating manner. This difference, as in the case of 

 Fythina with regard to KelUa, I regard merely of specific 

 importance. 



The valves, when viewed inside with the umbo upward, 

 recall the aspect of a bat, the outwardly recurved auricles 

 representing the ears. 



Tiie three valves upon whicli this description is based have 

 been presented to the British Museum by Mr. J. H. Ponsonby. 

 He informs me that he received them from Tasmania u)ider 

 the name of Pythina Deshaycsii, and therefore it seems likely 

 that this form is wrongly recognized there as that described 

 by Kccluz. 



EXPLANATION OF PLATE XIIL A. 



Fif/. A. Mylitta auriculata. Lett valve, interior. 

 Fi(j. B, „ „ liight „ „ 



Fir/. C. „ „ Lett ,, exterior. 



Fif/. 1). Mylitta Stoivei. Lett valve, interior. , 

 Fiy. E. „ „ liight „ „ 



Fuj. F. „ „ „ „ exterior. 



Fiy. Ci. Mylitta JJcshayesii. Iligbt valve, exterior. 



