286 



NEW YORK STATE MUSEUM 



and having a short hinge line. The species is of the type of the 

 Orthis lepidus Hall of the Hamilton shale fauna but is of 

 larger size than that little species is known to attain. The surface 



Dalmanella penouili 



of the valves is finely striate, the elevated radial lines differing in 

 size, a few being considerably larger than the rest. 



Dimensions. The average among several examples has a width 

 of 8 mm and length of 7 mm. 



Middle Devonic. Gaspe Basin, P. Q. 



Dalmanella drevermanni nov. 



Cf. Orthis tectiformis Walther. Neues. Jahrb. fiir Min, 



Beil. bnd 17, 1903. p. 164, pi. 3, fig. 4 a-c 

 Orthis circularis Sow. mut. p o s t u m a Freeh. Lethaea 



Paleoz. 1897. V. 2, pi. 24 b, fig. 8. nom. nud 



Orthis circularis Sow. D'Archiac & deVerneuil. Trans. Geol. 

 Soc. Lond. 1842. V. 6, pi. 38, fig. 12 {non auctorum) 



Orthis subcarinataHall Pal. N. Y. 3 : 169, pi. 12, fig. 7-21 



This shell, the only one of its type in the fauna, is essentially 

 a diminutive expression of Orthis subcarinata Hall of 



^HjUku.: 



J 



Dalmanella drevermanni 



the New Scotland beds. It has however affiliations with other 

 species, as cited above but the conditions of its occurrence oblige 

 us to regard the form as wholly mature; though with reference tO' 

 others its expression is immature. The exteriors of our shells 

 indicate fine and somewhat unequal striation, with rapid multipli- 



