WHiTEAVEs] DEVONIAN FOSSILS OP MANITOBA, ETC. 295 



dissimilar to any of the known species of AviiMi.lidd'. from the Devonian 

 rocks of North America or Europe. Their lobate outer margin, in the 

 adult state, gives them a certain general resemblance to Tridnciui, but 

 they seem to indicate a new generic type, which cannot be satisfactorily 

 defined until the characters of the interior of the \'alves are ascertained. 



(S.) AcTiNOPTEBiA BovDii, Conrad. 



For the synonymy of this species, with refei'enoes, see page 239. 



Pentamerus Point, Lake Manitoba, J. B. Tyrrell and J. F. Whiteaves, 

 1888 : four specimens. Dawson Bay, Lake Winnipegosis, on the south- 

 east side, on u, small island to the north of Whiteaves Point, D. B. 

 Dowling, 1888 : one specimen. South-west side of Lake Winnipegosis, on 

 ci small island ofi' Weston Point, one specimen : J. B. Tyrrell, 1889. 

 Dawson Bay, — on the south-east side, at Whiteaves Point (one specimen) 

 and on a small island north of that point (aljundant) ; on a small island 

 half way between Whiteaves and Salt Points (two specimens) ; on the 

 west shore, at the first small point north of the mouth of the Red Deer 

 Ki\-er (abundant) and on the second small point north of the same river 

 (nine specimens) : J. B. Tyrrell and D. B. Dowling, 1S89. 



Two or three additional species of Aviculidii? are indicated in the col- 

 lections made by Messrs. Tyrrell and Dowling, but the specimens in each 

 case are mere casts of the interior of the shell, which are too impei'fect 

 and badly preserved to admit of their being identified or described. 



(S.) GOSSELETIA. (Sp.) 



South-west shore of Dawson Bay, Lake Winnipegosis, about two miles 

 west of Salt Point, J. B. Tyrrell, 1888 : a single cast of the interior of 

 the closed valves of a species of this genus, which although evidently un- 

 described, is too imperfect to be properly characterized. 



(S.) MVTILAHCA INFLATA. (N. Sp.) 



Plate .38, figs. ,"5, 6 and 6a. 



Shall .small to medium sized, mytiloid, straight, strongly inflated : 

 lengtli,* from the beaks to the opposite extremity, about one third greater 

 than the maximum height or dorso-ventral diameter: thickness through 

 the closed valves a little greater than their height. Valves equal, tumid 

 in the ventral region, most prominent and suljangular on each of the 



* I)r. Paul Fischer (Man\iel de Conchyliologie, p. 1I(J.S) calls this the height and the 

 dorso-ventral diameter the length. 



