BRACHIOPODA. 



The retention, in the fossil state, of the pedicle, is a rare occurrence. Of 

 palaeozoic species, Mr. Davidson* has figured 

 an example of L. ? Lesueuri, in which the 

 impression of this organ is very distinctly 

 shown. More recently, Mr. Walcottj has 

 described a beautiful example of L. mqualis, 

 Hall, in which the narrow arm is seen pro- 

 truding from the aperture in the cardinal 

 area. By the favor of Dr. J. S. Newberry, 

 we have been allowed to figure a specimen 

 from the Waverly sandstone at Oil City, 

 Penna. (see Plate IV k, fig. 7), in which the 



\ . . FIG. 4. !■,....,. 



pedicle is also distinctly visible. The species Lingulaaqunlis,lUi]\. Unyula l Lcsveurl, Ucmaan. 

 , T 1.-1  T-w • 1 ^^''"' I'eilicle. With pedicle. 



IS the one identified as L. Scotica, Davidson, Atiei- walcott. Aner Davidson. 



by the Ohio geologists, and more recently described by Mr. Herrick^; as L. 

 Waverliensis. 



In regard to the myology of the palaeozoic Lingulas, we have satisfiictory 

 evidence that the arrangement of the muscles did not differ widely from that 

 in recent members of the genus. It is, however, not often that a palagozoic 

 specimen is found which has retained upon the surface of the shell, or left upon 

 the matrix, traces of the delicate muscular scars ; and in such instances usually 

 only the stronger impressions are discernible. A few examples have been figured 

 by recent American writers, which retain, in exquisite detail, not only the mus- 

 cular, but also the pallial impressions of the shell. Of these, one is a brachial 

 valve of the L. Whitii, of Walcott, figured in his Palaeontology of the Eureka 

 District ;§ another, an internal cast, representing the impressions on both dorsal 

 and ventral valves of iy. Elderi, Whitfield, figured by the author first, in the Amer- 

 ican Journal of Science,|| and subsequently, in the Report of the Geological Survey 



* Brachiopoda of the Budleigh-Saltei-ton Pebble-bed, p. 362, pi. xl, tig. IB. 

 t Proceedings of the United States National Museum, for 1888, p. 480. tig. 3. 

 X Bull. Denison Univ., vol. iv, pt. 1, p. 18, pi. iii, fig. 1. 1888. 

 § Page 109, pi. xiii, fig. 3, and pi. xxi, fig. 19. 1884. 

 I Vol. xix, p. 473. 1880. 



