UNGULINID&. P15 
TanorepIA, Lycett, 1850. 
Etym.—Dedicated to Sir Thomas Tancred, Bart., founder of 
the Cotteswold Naturalists’ Club. 
Syn.—Hettangia, Terquem. Paleomya, Zitt. and Goub., 1861 
Distr.—Fossil, 12 sp. Lias— Bath Oolite ; Britain, France. 
T. Dionvillensis, exix,65). T. curtansata, M. and L. (cxix, 66). 
T. (Paleomya) Deshayesii (cxix, 64). 
Shell trigonal, smooth; anterior side usually longest ; cardinal 
teeth 2-2, one of them small; a posterior lateral tooth in each 
valve; ligament external; muscular impressions oval; pallial 
line simple. 
This genus is closely related to Meekia of Gabb, Cretaceous, 
California, but differs in being closed instead of gaping anteriorly, 
as well as in wanting the peculiar anterior angularity of that 
type; which also presents some differences in the nature of its 
hinge-plate, and is said to have its ligament subexternal instead 
of decidedly external. 
Meexta, Gabb, 1864. 
Distr.—3 sp. M. radiata, Gabb (cxix, 67). Cretaceous; 
California. 
Shell oblong, subinequilateral, posteriorly rounded, anteriorly 
somewhat produced and turned upwards hook-like, terminating 
in a point; surface marked with striz of growth only; hinge 
with two robust, triangular teeth on the right valve, and one 
large and one small one on the opposite side, the large one being 
received between the two of the right valve; posteriorly on each 
side is an indistinct lateral tooth. A short robust plate separates 
the anterior muscular scar from the cavity of the beak. 
Famity UNGULINID A. 
Shell suborbicular, closed, sometimes a little irregular; hinge 
composed of two bifid, divergent cardinal teeth,and no laterals; 
ligament marginal, mantle-margins united, with pedal and anal 
openings ; foot vermiform. 
Uneuuina, Daudin. 
Etym.— Ungulina, like a hoof. 
Syn.—Clotho, Basterot, non Faujas. 
Distr.—4 sp. Senegal, Philippines, excavating winding gal- 
leries in coral. ? Carboniferous, Miocene. U. oblonga, Daud. 
(cxix, 68). 
Shell suborbicular; ligament very short; epidermis thick, 
wrinkled, sometimes black; hinge-teeth 2:2; muscular impres- 
sions long, rugose. 
Animal with the mantle open below, fringed; siphonal orifice 
single; foot vermiform, thickened at the end and perforated, 
