m 
MOLLUSCA. ACEPHALA. 
Lingula. 
PEDUNCULATA. 
Gen. lingula. — V alves equal, oval, flat, without teeth or 
elastic ligament ; peduncle cylindrical and cartilaginous ; 
margin of the cloak fringed with fine hairs. 
1. L. mytilloides. — Ovate, anterior end slightly truncated ; beak indistinct. 
— Mussel, Ure^ Ruth. 310. tab. xvi. 6. — Sower. Min. Conch, t. xix. f. 1, 2 — 
Carboniferous Limestone Casts of a shell imbedded in shale in the coal for- 
mation, figured by Ure, Hist. Ruth, 310. t. xvi. f. 5., probably belong to a 
species of this genus. They seem to have a mesial ridge, with diverging 
strije. 
2. L. tenuis. — Elongated, lanceolate, anterior end truncated. — Sovier. Min. 
Conch, t. xix. f. 3 London Clay. 
3. L. ovalis — Depressed, oblong-oval,’ anterior edge circular, beak very 
short — Sower. Min. Conch, t. xix. f. 4 London Clay f 
Gen. XCI. TEREBRATULA.— Inequivalve, apex of the 
largest valve perforated or emarginated for the passage of 
the circular ligament ; hinge consisting of a projection on 
each side the apex, and two elongated processes for sup- 
porting the arms on the smaller valve, projecting into the 
cavity. 
366. — T. cranium. — Shell ventricose, semitransparent, front 
margin slightly truncated ; surface finely shaggreened, and 
slightly wrinkled concentrically. 
Mull. Prod. 249. No. 3006. — Zool. Dan. t. xciv. f. 1 T. vitrea, Flem. 
Edin. Encyc. vol. vii. 96. t. 206. f. 2. — T. cranium, Mont. Linn. 
Trans, xi. 188. t. xiii. f. 2 — Occasionally brought from deep water by 
the cod-fishing-lines, Zetland. 
Length an inch and y^o^b, breadth i%ths less; bro wnish- white ; the shag- 
greening is remarkably delicate, and seen only by the help of a lens ; the la- 
teral teeth of the large valves are bifid ; those in the small valve give origin 
to the two projecting processes, which have a small tooth near their base, 
and project horizontally, upwards of three-fourths across the shell ; the con- 
centric wrinkles of growth occur irregularly ; peduncle simple. — To this pro- 
bably belongs the Anomia Terehratula of Turton’s Conchological Dictionary, 
p. 5.,^ where a reference is made to Da Costa’s Elements, 292. t. vi. f. 3., and 
where it is stated that a single specimen was dredged up alive in Dublin Bay, 
and placed in the Museum of the Dublin Society. 
367. T. pslttacea. — Shell oval, with regular fine longitudinal 
striae ; the beak much produced and curved ; the margin waved. 
List. Conch, t. ccii. f. 46. Turt. Conch. Diet. 5. t. xi. f. 42. Biv. Brit. 
236.— Cast ashore, after a severe gale, at Teignmouth, where Dr Tur- 
ton has since seen several fragments. 
