320 TESTACEOUS MOLLUSCA. 
« Surface minutely shagreened or punctated ; otherwise smooth.' 
T. VirreEa.— Anomia V. Born, p. 119.—Gm. 3347.— A. TErE- 
BRATULA, D. p. 294.—W. t. 11, f. 23.—T. V. Lam. 1.—E. t. 289, 
f.1—Sow. Th. 1, p. 353, t. 70, f. 56, to 59.— Gray, Brach. p.17, f. 3. 
Rounded-ovate, ventricose, slightly diaphanous, very smooth, whitish 
horn-coloured, devoid of mesial ridge or furrow, subequivalve ; outline 
nearly straight; upper valve dorsally rounded, recurved and slightly 
acuminated ; perforation small, entire, rather oblique, with a thick- 
ened margin; cardinal area indistinct, rounded, with united indistinct 
deltidia. | Lower valve nearly circular, slightly truncated ventrally ; 
loop small, only one-fourth the length of the shell, arched and vaulted 
at the tip. Inner margin entire. Mediterranean.” 
T. Uys... Brod. Z..P.1883 ; 24. T. 1, 4.22, f. 2.—Sow. ThA, 
p. 858, t. 70, f. 58, 4, 5.— Gray, Brach. p. 18. Oblong, gibbous, 
smooth, pale, slightly diaphanous, devoid of mesial ridge or furrow ; 
marginal line sloping from the apex, then somewhat flexuous. Upper 
valve dorsally produced, its apex reflected and truncated ; perforation 
large, entire, very oblique, with a thickened margin ; cardinal area 
indistinct, rounded; deltidia small, united, concave. Lower valve 
ovate-oblong ; internal appendage formed of two rays setting off from 
the hinge and expanded at the ends. Inner margin entire. Gulf 
of Tehuantepec. The punctation of surface is coarser than im 
VITREA. 


1 The following more scientific division, by Dr. Gray, is much 
preferable, yet is scarcely to be practised without injury to the 
specimens. By the sequence of species, aided by the notes, it 1s 
made available to our readers :-— 
TEREBRATULINA. Hinge-line decidedly curved ; margin even or only 
slightly waved ; loop attached to the hinge-plate only. Includes 'TERE- 
BRATULA, TEREBRATULINA, WALDHEIMIA. 
Macastna. Hinge-line not much, if at all, curved; smaller valve 
with a longitudinal depression; loop attached to the septum in the 
middle of the smaller valve. Includes TEREBRATELLA, Macas, Bov- 
cHARDIA, MrcreruiA, Morrista, Kravssia. 
Aretopina. Transversely oblong or semicircular ; loop attached to 
the surface of the valve. Contains ARGIoPE only. 
2 ‘This and the succeeding species (the latter with doubt) are the 
only recent shells included by Gray in TEREPRATULA proper :— 
TeREBRATULA. Smooth, convex; beak truncated and perforated ; 
foramen circular; deltidium of two pieces, frequently blended; loop 
very short, simple, attached by its crura to the hinge-plate. 
