308 TEREBRATULID. 
TEREBRATULA, Muller, 1776. 
Etym.—Diminutive of terebratus, perforated. Lamp-shell. 
Syn.—Lampas, Humph., 1797. Gryphus, Muhlfeldt, 1811. 
Epithyris, Phil., 1841. Liothyris, Douvillé, 1879. 
Distr.—8 sp. West Indies, Mediterranean ; 90-250 fathoms 
on nullipore mud. (Forbes.) Vigo Bay, Falkland Islands, 
Japan. Fossil, very numerous species. Triassic—; world-wide. 
T. maxillata, Sowb. (cxxxiv, 2). T. vitrea, Linn. (cxxxiv, 6, 7). 
T. sella, Sowb. (exxxiv,5). T. Phillipsit, Morris (cxxxiv, 3, 4). 
Shell 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. 
Animal attached by a pedicel; brachial disk trilobed, centre 
lobe elongated and spirally convoluted. 
Douvillé has proposed the name Liothyris for shells without 
folds, like 7. vitrea, L. (cxxxiv, 6,7), but there are so many 
intermediate stages that the division cannot be maintained; some 
young individuals are unfolded, but acquire the folds in growth. 
pyaorr, Link, 1830. (Diphytes Schrot., 1779. Antinomia, 
Catullo,1850. Pugites, DeHaan, 1833. Glossothyris, Douvillé, 
1879.) Ventral valve bilobed when young; when adult, the lobes 
unite, leaving a round hole in the centre of the shell. Jurassic 
and Cretaceous; Southern Europe. 7’. diphoides, d’Orb. (cxxxiv, 
8-10). 7. diphya, Colonna (cxxxiv, 11>. 
DicTYoTHyRis, Douvillé, 1879. Ventral valve two-folded with 
a median depression; dorsal valve with a strong median swelling, 
bordered by channels; surface radiately striate, crossed by con- 
centric growth-lines forming tubercles at their intersection. 
Jurassic and Cretaceous. 
cm@NOTHYRIS, Douvillé, 1879. Shell oval, smooth; tooth-plate 
strongly developed ; apophyses independent of the cardinal teeth, 
from which they are separated by a diverging slit; a septum 
present, as in Waldheimia. 7. vulgaris, Schloth. (cxxxiv, 12). 
DieLasma, King, 1859. 
Syn.—Epithyris, King (part), 1850. Seminula, M’Coy (part), 
1855. Cyrptacanthia, White and St. John, 1868. 
Distr.—Permian—; Eur., N. Am. JD. elongata, Schloth. 
(cxxxiv, 13). 
Shell with lamelle supporting the teeth of the neural valve, 
a short loop as in Terebratula but more abruptly sinuated ante- 
riorly, and with the central lamina of the hinge-plate in the 
hemal valve produced in the form of a mason’s trowel, and 
supported beneath by a mesial septum. 
TEREBRATULINA, d’Orbigny, 1847. 
Syn.—Agulhasia, King, 1871. 
Distr.—8 sp. United States, Norway, Australia, Cape, Japan ; 
