BRACHIOPODA. 



TJnyuld ii.quiili.i, UM. I.iiujuUi ? LcsueuH, Itouault. 



Willi peilii'lo. With pellicle. 



Alter Walcott. Al'lev Davuisox. 



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

 palaeozoic species, Mr. Davidson* has figured 

 an example of />. ? Lesuewi, in which the 

 impression of this organ is very distinctly 

 shown. More recently, Mr. Walcott f has 

 described a beautiful example of L. iRifualis, 

 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 

 pedicle is also distinctly visible. The species 

 is the one identified as L. Scolica, Davidson, 

 by the Ohio geologists, and more recently described by Mr. HerrickI as L. 

 Waverliensis. 



In regard to tlie myology of the palaeozoic Lingulas, we have satisfactory 

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

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

 specimen is found which has retained upon the surfoce 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 L. Elded, Whitfield, figured by the author first, in the Amer- 

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



* Bi-achiopotla of the Budleigh-Saltertoii Pebble-bed, p. 362, pL xl, tigf. 16. 

 t Proceedings of the United States National Museum, for 18S8, p. 4S0, (\g. 3. 

 X Bull. Uenison Univ., vol. iv, pt. 1, p. IS, pi. iii, tier. 1. 1S88. 

 § Paye 109, pi. xiii, fig-. 3, and pi. xxi, fig. 19. 1S84. 

 II Vol. xix, p. 473. 1880. 



