134 CONTRIBUTIONS TO CANADIAN PAL/EONTOLOGY. 



with the description and figure of the Nevada shell which Meek has 

 identified with the H. Lommelli of European authors. 



Small slabs of limestone, covered with numerous valves of a Halohia 

 which may possibly represent an extreme local variety of this species, 

 were collected by Dr. Dawson in 1878 at Section Cove, north end of 

 Barnaby Island, Q.C.I., and in 1885 in a bay five miles west of Cape 

 Commerell, at the north end of Vancouver Island. The specimens 

 from these two last mentioned localities differ from those from Houston 

 Stewart Channel in having much finer radiating ribs, which, however, 

 are flattened and broader than the fine linear grooves between them, — 

 and in the circumstance that the beaks are usually, though not always, 

 placed much farther forward. As ali'eady remarked (on page 127), 

 similar specimens were collected by Mr. J. W. McKay at Glenora on 

 the Stikine Eiver. 



Halobia ocoidentalis. (N. Sp.) 

 Plate 17, figs. 5 and 6. 



Left valve (the only one that has been recognized with any cer- 

 tainty) rather strongly convex, especially in the umiional region : 

 slightly inequilateral and a little higher than long: marginal outline 

 subovate, somewhat pointed below, broadest a little above the middle, 

 but truncated distinctly and transversely at the hinge line above. 

 Posterior margia broadly rounded ; anterior side a little shorter than 

 the posterior, the upper half of its margin nearly straight, vortical, 

 and at length forming a nearly rectangular junction with the cardinal 

 border above : pallial border narrowly rounded or obtusely pointed a 

 little iu advance of the midlength. Cardinal border straight, very 

 little shorter than the maximum length of the valve : posterior 

 cardinal angle rounded oft', the antei-ioi- subangular : beak moderately 

 prominent, appressed and placed a little in front of the middle. 



Surface marked by numerous thread-like, radiating raised lines, 

 which are narrower and often very much narrower than the spaces 

 belween them, especially on the lower half of the posterior side of the 

 shell. Ohai'acters of the inteiior of both valves unknown. 



Dimensi<jns of the type specimen: maximum length, twenty-two 

 millimetres; greatest height, twenty-five mm. 



Liard Eiver, about twenty-five miles below Devil's Portage, R. G. 

 McConnell, 1887 ; one perfect and wcll-presei'ved cast of the interior 

 of a left valve. 



At the same locality and date two other specimens were collected. 



