402 Canadian Ptecord of Science. 



his Fauna No. 3, the representative of the Silurian (Upper 

 Silurian), as distinguished from what is now called the 

 Camhro-Silurian or Ordovician System. In 1885, however, 

 in volume V, part 1 (Lamellibranchiata) of the '•' Palaeon- 

 tology of the State of New York," Professor James Hall 

 described and figured fifteen species of Panenka from the 

 Devonian rocks of the United States. Some of these species 

 had previously been referred to Pterina and Monotis by 

 Conrad and S. A. Miller, and by Hall himself to Cardiola. 

 The names of three additional species of Panenka from the 

 Devonian of North America are given in S. A. Miller's 

 "North American Geology and Palaeontology," published 

 in 1889. 



This genus was, and still is, based exclusively upon the 

 external characters of the shell, the hinge dentition, muscu- 

 lar impressions and pallial line of the interior of the valves 

 being unknown. It is described as having no distinct car- 

 dinal area, like that of the Arcudce, but some species are 

 said to show obscure evidence of a ligamentary groove. 

 The systematic position of Panenka is therefore quite uncer- 

 tain. It is placed by Hall in the Cardiidx, but Eudolf 

 Homes has constituted a special family, which he calls the 

 Pr&cardiidce, for the reception of Proecardium, Panenka&nd 

 several other similar and apparently closely related genera 

 described by Barrande. This latter view of its relations, 

 which seems to be the most satisfactory one in the present 

 state of our knowledge, is adopted by Dr. Paul Fischer in 

 his i( Manuel de Conchyliologie." In that volume the fam- 

 ily Praicardiidoe is placed between the Grammysiidce and 

 the Pholadomyidce, but its author states that it seems to him 

 to have closer relations with the Anatinacea than with any 

 other suborder of the Dibranchiata. The species indicated 

 by the four specimens collected by Mr. Lambe may be 

 described as follows. 



Panenka gbandis. (Sp. nov.) 



Plate 1. 



Shell very large, attaining to a length of from six to nine 



