388 



NucuLA HoRNBYENSis, Whiteaves. 



Plate 46, fig. 4. 



Nucula Hornbyensis, Whiteaves. 1896. Trans. Royal Soc. Canada for 1895, Second 

 Series, vol. i, sect, iv, p. 122, pi. 3, fig. 2. 



Original description and remarks. — " Shell of medium size for the 

 genus, compressed convex, subellipfcical in marginal outline, rather oblique 

 and very inequilateral. Anterior or longer side obliquely subtruncated 

 at its extremity above and rather narrowly rounded below ; posterior or 

 shorter side very regularly but narrowly rounded at the end ; ventral 

 margin broadly rounded, but rather more convex posteriorly than ante- 

 riorly ; superior border nearly straight but slightly descending in front of 

 the beaks, and sloping obliquely and much more rapidly downward 

 behind them ; beaks small, incurved and recurved, projecting very little 

 above the highest level of the superior border, placed behind the mid- 

 length, and in one specimen almost terminal. 



" Surface almost smooth, marked only by a few faint concentric striae 

 of growth ; test thin. 



" Dimensions of the largest specimen known to the writer : length, 

 eleven millimetres ; height, eight millimetres. The specimen figured is 

 not quite six millimetres in length. 



"North-west side of Hornby Island, in the ' Middle Shales or Division 

 D' of Mr. Richardson's Comox Section, W. Harvey, 1894: one right 

 valve, one left valve, and a somewhat crushed specimen with both valves, 

 each with the test preserved. 



" These specimens may represent a variety of Nucula solitaria, but if 

 Mr. Gabb's figure of that species is correct, it must have a very different 

 marginal outline. His illustration represents a much more triangular 

 shell than that of JV. Hornbyensis, with a more prominent beak, and more 

 pointed at both ends. 



" Nucula Traskana, Meek, from the Cretaceous rocks of Vancouver 

 Island, was described from a single worn cast of the interior of the shell, 

 which has never been figured and has since been lost. Mr. Meek states 

 that the specimen was ' probably provided with a distinct lunule,' and 

 that ' the species will probably be recognized by its ventricose trigonal 

 ovate form and nearly central beaks.' This description is quite inappli- 

 cable to the specimens from Hornby Island, in which the lunule and 

 escutcheon are both obsolete." 



Since this description was written, two other specimens of N. Hornby- 

 ensis, which are now in the Museum of the Survey, were collected at 

 Hornby Island by Mr. Harvey in 1895. The larger of these, which is 



