BRACHIOPODA 363 
it, are found in the Upper Oolite and throughout the Chalk 
series and London Clay.* 
FAMILY J.—TEREBRATULIDA. 
Shell minutely punctate; usually round or oval, smooth or 
striated ; ventral valve with a prominent beak and two curved 
hinge-teeth ; dorsal valve with a depressed umbo, a promi- 
nent cardinal process between the dental sockets, and a slender 
shelly loop. 
Animal attached by a pedicle, or by the ventral valves; oral 
arms united to each other by a membrane, variously folded ; 
sometimes spiral at their extremities. 
ffs 
LA 
LE 
ZZ 
Sry 
LSC RRSY 
Qh LE 
QSY ! 4 Zo 
SIS ty ‘i y ae 
ES ~ CEE 
SSSA Ne 
S aS 
== 3) ——— 
SAA By SS —— 
ZZ; IN — 
SB if S 
nN \ 
\ \ 
Fig. 147. Terebratula vitrea, Born. 
TEREBRATULA, (Lihwyd.) Brug. Lamp-shell. 
Htymology, diminutive of terebratus, perforated. 
Synonyms, Lampas, Humph. Gryphus, Muhlfeldt. Epithyris, 
Phil. 
Types, T. maxillata, Pl. XV., Fig. 1. (= Ter. minor-sub- 
rubra, Lihwyd. Anomia terebratula, L.) TT. vitrea, Fig. 147. 
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 
(Fig. 147, A). 
Animal attached by a pedicle ; brachial disk tri-lobed, centre 
lobe elongated and spirally convoluted (Fig. 147, B). The 
young of 7. diphya (Pygope of Link) has bi-lobed valves 
(Pl. XV., Fig. 2); when adult the lobes unite, leaying a round 
hole through the centre of the shell. 
* The author has to acknowledge his obligation to Mr. Davidson for the use of 
the notes, drawings, and specimens, assembled during the preparation of his great 
work on the “ British Fossil Brachiopoda,” printed for the Paleontographical 
Society; to which work the student is referred for more copious descriptions and 
illustrations, 
R2 
