12 
MUSEUM BULLETIN NO. 29. 
Family, Mytilidb Fleming. 
Genus, Brachydontes Swainson. 
\ 
Brachydontes aihabaskaensis n. sp. 
Plate Y, figures 1, 2. 
Description. Compared with Brachydontes muUilinigera Meek this 
species has similarly, a well-defined post umbonal ridge, small incurved 
beaks, and the radiating surface striae becoming stronger dorsally and finer 
ventrally and anteriorly; but it has a less arcuate outline, a straight er 
umbonal ridge, a hinge-margin less inclined to the anterior margin, a less 
cuneate posterior outline, it is proportionately narrower, the ventral margin 
is not strongly incurved, but only slightly so, and the radiating striae 
are much finer. The umbonal ridge is followed below by a slight sulcus. 
It differs from Brachydontes tenuisculpta Whiteaves in much the same 
characters, Whiteaves’ species being very close to Meek’s; compared with 
the type specimen, the Athabaska species has much finer radiating sculp- 
ture. The radiating stride of this species are exceedingly fine. Height 
16 mm., length 35 mm. 
Horizon. Hare in the Clearwater formation, Athabaska river, Alberta. 
Collection. Victoria Memorial Museum; holotype, Cat. No. 5403; 
paratype, Cat. No. 5404. 
Order, Teleodesmacea Dali. 
Family, tellinid^b Deshay es. 
Genus, Tellina Linnaeus. 
Tellina dowlingi n. sp. 
Plate 7, figures 31 4, 5, and 6. 
Description. The important character of this species is the subangular 
anterior end, which gives, in some specimens, a pronounced cuneate outline; 
the antero-cardinal margin is straight to slightly concave and directed 
downward at an angle of about 45 degrees; basal margin rounded; postero- 
cardinal margin straight, parallel to basal margin; posterior margin 
rounded below, obliquely truncate above; beaks small, subcentral, incurved 
and curved slightly forward; post umbonal slope rounded, escutcheon 
broad; lunule very narrow, quite convex to somewhat depressed; surface 
covered by even lines of growth; ligament external; pallial sinus narrow 
and subangular. The ratio of height to length varies from 1:1 to 2:3. 
Tellina carteroni d’Orbigny from the Neocomien of France is proportionately 
longer, more rounded anteriorly, and more depressed. Height 26 mm., 
length 40 mm. This species is named after D. B. Dowling. 
Horizon . Rather common in the Peace River formation, Peace river, 
and in the Clearwater formation, Athabaska river, Alberta. 
Collection. Victoria Memorial Museum; holotype, Cat. No. 5405; 
paratypes, Cat. Nos. 5406, 5406a, 5406b. 
