144 PERMIAN FOSSILS. 
Genus Pygope, Link, 1830. 
The apophysary system of this group resembles that of the last genus; but a 
separation appears to be warranted by some presumed differences in their labial 
appendages. From the singular prolongation or separation of the lateral halves, and 
the undeveloped character of the medio-longitudinal region of the shell of Pygope 
diphya, 1 am led to suspect that the labial appendages of its inhabitant were exceed- 
ingly long, and separated from each other nearly at their base; in which case the 
lateral halves of the shell would each be occupied with the free and projecting portions 
of these organs; and there would consequently be no reciprocal connexion between 
them except in the buccal region—a character unparalleled in any other known 
Palliobranchiate genus, with perhaps the exception of Dicelosia. 
Pygope is only known to occur in the latest secondary deposits. 
Genus Ludesia,' King. 
TEREBRATULA, Auct. 
2™5 Supp., 1®* Div. Bracutop., Hudes-Deslongchamps, 1837. 
Diagnosis.—A plaited Terebratulidia. /arginal outline more or less oblong longi- 
tudinally. Beak projecting ; truncated with a large foramen, which is bounded inferiorly 
by a deltidium. Punctures moderate in size. 
Type TLerebratula orbicularis, J. Sowerby. 
Lfudesia is proposed with some hesitation ; because it bears so close a resemblance 
to the striated division of Zerebratula, represented by T. caput-serpentis, which is 
suspected to be the type of A. dOrbigny’s Zerebratulina, that it is doubtful whether it 
is a distinct genus. 
Genus Zerebratella, A. @Orbigny, 1848. 
Not being acquainted with the diagnosis of this group according to the views of its 
author, I make free to characterise it as having a loop projecting considerably into the 
cavity of the shell, and attached posteriorly to the crural base, and anteriorly to the 
medio-longitudinal plate. 
Type Zerebratula Chilensis. 
1 This genus is dedicated to M. Eudes-Deslongchamps. 
