ORDER III TELEODESMACEA 395 
Trapezium (Humph.), Megerle (Libitina, Schum.; Cypricardia, Lam.) Shell 
elongate, trapezoidal, concentrically, or more rarely radially sculptured, often with a 
posterior keel; three cardinal teeth in each valve, the posterior in the right valve 
often bifid. Jura to Recent. 
Plesiocyprina, Mun.-Chalm. Jura. Ctcatrea, Stol. Cretaceous. Coralliophaga, 
Blainv. Tertiary and Recent. 
Arctica, Schum. (Cyprina, Lam.), (Fig. 702). Oval or rounded, inflated, concen- 
trically striated ; beaks prominent, curved, cardinals three in each valve, the left 
posterior often bifid, the middle left cardinal largest, and the posterior ridge-like. 
Abundant in the Jura and Cretaceous, and represented by one or two living 
species. 
Venilicardia, Stol. (Fig. 703). Cretaceous. Pygocardia, Mun.-Chaln. Tertiary. 
Veniella, Stol. (Venilia, Morton; (?) Goniosoma, Conr.), (Fig. 704). Left valve 
with the anterior cardinal strong, sub-triangular. Cretaceous and Tertiary. 
Superfamily 2. ASTARTACEA. Dall. 
Lobes of the mantle free ventrally; lateral laminae obscure, when present distant 
from the cardinals. 
Family 3. Curtonotidae. Dall. 
Shell short and heavy, with sub-terminal beaks ; valves free, equal, closed; area 
obscure ; ligament as in the Astartidae; adductor scars, especially the anterior, deep ; 
pallial line simple; hinge plate broad, without lateral laminae; the formula of the 
L0101 on L010 
cardinals = 
es . Devonian and Carboniferous. 
R1010.-R101 : 
This group is inserted conformably with the opinion of Neumayr, who regards it as the 
radical of the Astartidae. 
Curtonotus, Salter. Oval, cardinal border thick, with one very strong tooth in the 
left, and a strong anterior and thin posterior tooth in the right valve. Scars of the 
adductors strong, especially the anterior. Devonian; England. 
Prosocoelus, Keferst. Devonian. Protoschizodus, de Kon. Carboniferous. 
Family 4. Astartidae. D’Orbigny (emend.) 
Shell substance cellulo-crystalline, with a pronounced epidermis ; shell rounded or 
sub-triangular, usually with concentric or not radial sculpture ; valves equal or sub-equal, 
free, closed ; area distinct ; ligament and resilium external, parivincular, opisthodetic ; 
beaks prosococlous ; adductor scars sub-equal, with a distinct anterior pedal scar ; pallial 
line simple; hinge plate distinct, hinge with anterior and posterior 
lateral teeth and their respective sockets, usually more or less obsolete ; 
cardinal teeth not bifid at the summit, the terminal teeth frequently 
obsolete. Lobes of the mantle free ventrally, not produced into siphons. 
Trias to Recent. 

Fic. 705. 
Astarte, Sow. (Crassina, Lam.), (Fig. 705). Roundly triangular | Astarte Voltzi, 
> oval. rath ressed. thick: s ] a jeally-scul nad : Ziet. Middle Jura ; 
or oval, rather compressed, thick ; smooth or concentrically sculptured ; Gundershofen, 
lunule impressed ; right anterior cardinal strong. Alsace. 1/}. 
A number of genera have been associated with Astarte which probably belong elsewhere. 
The following sub-genera, however, are worthy of recognition :—Coelastarte, Bohm ; Preconia, 
Stol. ; Crassinella, Bayle non Guppy (Fig. 706) ; Prorokia, Bohm. Jura. Lriphyla, Gabb. 
Cretaceous. Grotriania, Speyer ; Goodallia, Turton (Fig. 708) ; Rhectocyma, Dall; Woodia, 
Deshayes (Fig. 707). Tertiary and Recent. 
