144 OEETACEOUS PELECYPODA 



are vertically erect, laterally compressed, and generally bifid, with the exception 

 of the most anterior tooth in the left, or sometimes in both yalyes : this peculiarity 

 is indeed so characteristic as compared with the hinge of Venus that no doubt can 

 be entertained in the determination of the shell ; it is the most constant of all 

 the other characters of the sub-family, and when combined with a compressed 

 shape of the shell, as, for instance, in V, literata, Linn., the resemblance of such 

 forms to Venerupis (of the Fetricolid^J is, as already mentioned, striking. 

 The only rather solid shells are those belonging to the type of T. pinguis, Chem,, 

 mostly approaching in character some species of Meretrix, 



In 1864 Dr. Ed. Eomer published in the Malaco-zoologische Blotter "a 

 critical synopsis of all the species belonging to Tapes, a sub-genus of the genus 

 Venusy The author admits four sections of Tapes, each under a different name. 

 They are FaratapesC=Textrix; Eom.,) Farembola, Amygdala, and Hemitapes. 

 I have already recorded my opinion with regard to the propriety of the names 

 which Dr. Romer giyes to his sections or sub-sections. I haye also stated 

 that it would not be adyisable to interfere with Dr. E5mer's work as long as it is 

 in progress. So far, therefore, as the recent forms are concerned, I shall restrict 

 my remarks to a few suggestions, illustrating my ideas on the classification of the 

 TAPESiNu^ by quotations of well known species as types. 



1. Faratapes, StoL, 1870, (Textrix apud Eomer, not idem Blackwall or 

 Sundewal, 1833, AracJinoideaJ, Type P. textrix, (Chem.). Shell much elon- 

 gated, compressed, outer surface smooth, 



2. Eemitapes apud Eomer; type Tapes pinguis, (Ghem.). Shell inflated, 

 solid, yentricose, especially at the umbones, which are incuryed^ more or less 

 narrower posteriorly ; outer surface smooth. 



2a» E5mer refers to the aboye as a special section Venus rimularis of 

 Lamarck, which has a rhomboidal shape and concentric sulcations. This is a 

 somewhat different type of shell, and could be considered, moreover, as a section of 

 Fullastra, or perhaps still better as distinct from both and classed with T, denti- 

 culata. Sow., the Calif ornian Tap. straminea, &c., the shells of these species being 

 solid, with the inner margin crenulated. 



8. Fullastra, Sow., 1827, (as emended by H. and A. Adams). Shell 

 elongated, moderately inflated, anterior side peculiarly narrowly rounded; 

 surface of yalyes concentrically sulcated or striated ; pallial sinus ascending, rather 

 higher than in other forms of Tapesince, The type of this is Ven, malabarica, 

 Chem., or Tap. turgidula, Desh. The species are rather numerous in our eastern 

 seas ; Venus cor of Sowerby from Cutch also belongs to it. 



3a. A number of species which are strongly inflated, cuneiform, thick and 

 short in front, and gradually becoming narrow towards the posterior end, thus 

 in this respect very much resembling Eemitapes, appear to form a special section. 

 Chemnitz's Ve^ius striata is the most characteristic species of this group. 



4. Tapes, Megerle, 1811, (Faremhola apud Eomer). Shell sub-rhomboidal, 

 compressed, beaks yery small, surface of shell concentrically ridged or sulcated, 



