TELLINA. 35 
anomale, in medio laterum, distantes, secant oblique ad angu- 
lum acutum strias ordinarias confertiores, que, nota huic spe- 
cialis.” The whole description in the ‘Museum’ so fairly 
applies to that common species (so abundant and diffused 
that it would have been strange, indeed, if Linneus had not 
known it) that the 7’. gart may be referred to it with a double 
note of interrogation. The presence of that shell (Brit. Moll. 
pl. 19, f. 3) in the Linnean cabinet is devoid of authority, since 
our author has not enumerated the 7’. gari among the types in 
his own possession. If the passage just copied does not require 
that the anomalous strie should be present together with the 
concentric ones, so as literally to traverse them, but only means 
that they run obliquely on one side of the shell, then in all 
probability several species were reckoned as varieties in the 
work referred to; e. g. the var. y. might be P. maculosa. 
Many shells have been looked upon, by various writers, as 
the representatives of this ambiguous species. Born, guided 
by Argenville’s figure, selected a nearly smooth shell (Vs. ves- 
pertina or a very close ally); Chemnitz two, Ps. cerulescens and 
Ps. pulchella, to the former of which it is doubtfully referred by 
Lamarck, to the latter decidedly by Wood and Dillwyn. The 
‘‘ antice valde rugosa” is sufficient to exclude all the three; 
the recorded peculiarity of sculpture is utterly unlike that of 
vespertina. By the last-mentioned writers Ps. maculosa (or at 
least the figure 94 in Chemnitz, which much resembles it) is 
included in it likewise, and, if we are to understand by “in 
medio laterum,” in medio teste, that shell certainly approaches 
it more nearly than any other at present known to me. If, on 
the contrary, we hold that expression equivalent to in medio 
arez laterum (i. e. the lateral area), then some such species as 
Ferroensis has a better claim to the Linnean appellation: 
Schroter, indeed, has figured that species for 7’. gar, but his 
description is extracted fromthe ‘Museum Ulrice.’ 
Tellina fragilis. 
The Diodonta fragilis (Chemn. Conch. Cab. vol. vi. pl. 9, f. 
84) of the ‘ British Mollusca’ is marked for this species in the 
Linnean cabinet. 
