ANIMALS. 145 
Genus Wegerlia, King. 
Diagnosis.—A transversely-oblong, uni-areagerous Terebratulidia. Umbone very 
slightly projecting. sswre or foramen large, emarginate, and situated in the centre 
of the area. Cardinal muscular fulcrum excavated. Loop somewhat quadrate ; confined 
to the posterior half of the shell; attached posteriorly to the crural base, and anteriorly 
to the medio-longitudinal plate. Inner surface of valves radiately pimpled.  Punctures 
large. 
Type Anomia truncata, Gmelin. 
The species just noticed is included by M. d’Orbigny in Zerebratella; but as it 
manifestly possesses a generic character of its own, I have been induced to consider it 
as typifymg a distinct (and in appearance a widely separated) genus. Perhaps the 
proper position of MWegerlia is in the family Rhynchoride. 
Genus Valdheimia,’ King. 
Diagnosis—A smooth or widely plicated, longitudinally-oblong Terebratulidia. — 
Umbone projecting; and truncated with a rather large foramen, which is bounded 
inferiorly by a bisected deltidium. Loop forming a nearly complete ellipsis; projecting 
considerably into the cavity of the shell; deeply folded back on itself so as to nearly 
reach its crura; and attached simply to the crural base. Labial appendages attached 
to the loop throughout their entire length. Puwnctures large. 
Type Zerebratula Australis, Quoy et Gaymard. 
Waldheima differs from Terebratula in the form of the loop, and the character of 
the labial appendages,’ both of which structures, in the former, are intimately connected 
with each other, the loop supporting the labial appendages throughout their entire 
length; whereas in the latter, these organs project considerably beyond a small 
anneliform apophysis, which mainly serves as a visceral support. The loop in the 
typical species of Valdheimia, owing to its bemg so deeply recurved, is in the form of 
a double ellipsis ; and it projects about two thirds of the length of the shell. 
Several Jurassic Zerebratulide appear to belong to the present genus. 
1 This genus is dedicated to the author of a paper entitled ‘ Entwurf eines neuen Systems der Schaalthiere 
von J. K. Megerle v. Muhlfeld,’ in the Freunde zu Berlin, &c., 1811. 
2 This genus is dedicated to His Excellency Fischer de Waldheim, to whom we are much indebted for 
several valuable contributions on the Paleontology of Russia. 
3 There is evidently a wide difference between Waldheimia and Terebratula in their labial appendages ; 
but I am not prepared at present to enter on the subject. 
