JUKES BROWNE : TAPES AUREUS AND ITS ALLIES. 277 



Tapes aureus Gmeliri, typical form. 

 ,, ,, var. catenifera Lam. 



,, ,, var. texturata I,am. 



,, ,, \?iX. piilchella'L.diXQ.. 



,, ,, var. elongata B.D.D. 



There can be no doubt that the second and third of these names 

 represent distinct natural groups which desevre to be distinguished 

 by special names, whether we regard them as species or only sub- 

 species, and that the last two are also well-marked forms. They may 

 be considered in the order above given. 



I. — Tapes catenifer, or Tapes aureus var. catenifera, is smaller 

 than typical T. aureus, its average length being from 24 to 28 mm., 

 while that of T. aureus is from 26 to 32 mm., and sometimes up to 

 40 mm. The shell is oval and often elongate-oval, less convex than 

 T". aureus, and its substance much thinner. The concentric striation 

 is finer and more regular and the radiating lines are obsolete or very 

 faintly marked. Inside the colour is usually yellow or yellowish- 

 white, but sometimes violet or purple. The muscular impressions are 

 small, and the pallial sinus larger than in T. aureus. 



Under this head are placed the forms named by Lamarck yf^^ni^c?, 

 bicolor, 2i\\d. petalina, the first differing little from the type, the second 

 being whitish with a blotch of brown on the posterior side, and the 

 third being of a violet colour inside and darkly variegated outside. 

 These are merely colour-variations, but the authors recognise two 

 shape-varieties, viz., bourguignati (Locard), which is much elongated 

 posteriorly, and grangeri (Locard), which is regarded as a connecting- 

 link with the next form T. texturahis, being larger and higher. 



2. — Tapes texturatus. This is a larger shell, averaging 35 to 

 40 mm. in length, broadly and regularly oval, but generally more or 

 less compressed. The concentric grooving is very fine, and the sur- 

 face of the shell is always glossy and glistening, as well as being 

 usually brightly coloured. In texture, it is very thin and brittle, thus 

 contrasting strongly with the shell of T. aiireus. Inside it is either 

 white, yellow, or purple, according to the external colour-variations. 

 The muscular impressions are of moderate size but shallow, and the 

 pallial sinus is not proportionately so large as in T catenifer. 



In this group, the authors of the " Mollusques du Roussillon " 

 placed the T. florida of Reeve {non Lam.), the floridella of Lam., 

 7nabillei, rostratus, nitidosus, and retortus of Locard, besides radiatus, 

 luteus, and other colour-varieties. M. Dautzenberg, however, has 

 kindly informed me that he now excludes the Venus floridella of 

 Lamarck, because, having examined the type, he finds that to be an 



