TRANSACTIONS OF SECTION D. G87 



Hypotheria. The Goinpliodontia, however, with the exception of Tritylodon, 

 show a marked trituhercular pattern in their superior molars (especially Diade- 

 modon mastacus) and tend to confirm the author's hypothesis that the multituber- 

 culates are of trituhercular origin. 



The general conclusion is that the Theriodontia stand nearer the ancestral 

 mammalia Prototheria, Metatheria, and Meseutheria than any other known division 

 of the Reptilia. 



6. Description of Sjjecimens of Sea-trout, Caplin, and Sturgeon from 

 Hudson Bay. By Professor Edward E. Prince, Ottawa. 



The author referred to the special interests attaching to specimens illustrative 

 of the fish fauna of Hudson Bay, the faunistic resources of which are almost wholly 

 unknown. 



Distinguished explorers like Dr. E. Bell, Mr. J. Burr Tyrrell, Mr. A. P. Lowe, 

 and others, chiefly members of the statt' of the Geological Survey of Canada, have 

 gathered information regarding the fish in the remote northern areas referred to ; 

 their special work, of a geological and geographical character, prevented systematic 

 zoological investigations. The specimens described by the author were placed in 

 his hands by Dr. Bell and Mr. Lowe. 



The salmon-trout from Ungava Bay is the Salmo Hearnii, originally described 

 in Franklin's first journal. It is really a Salvelinus, and is no doubt the Salve- 

 Jinus alpinus stagnalis of Jordan and Evermann. It must be noted, however, that 

 the Salmo stagncdis of Fabricius (1780), inhabiting small lakes in Greenland, is 

 non-migratory. If it be non-migratory, or if it does migrate to the sea, and then 

 becomes, as is stated, of a plain silvery colour, the specimen under review is not 

 identical with it. At any rate, the present specimen, taken, as Mr. Lowe states, on 

 the east coast of Hudson Bay to the north of Cape Jones, and very abundant in 

 the streams entering Ungava Bay and along the northern coast of Labrador, is 

 characterised by the three features mentioned below. First, it is migratory and 

 ■captured in vast numbers in tidal waters in Ungava Bay and other localities. 

 Secondly, it exhibits large disc-like spots of a pale flesh tint, rather larger than a 

 pea in circumference, and extending from the shoulder to the tail, and slightly above 

 the lateral line. Thirdly, the scales are exceedingly small, somewhat deeply im- 

 bedded in the integument, and numbering at least 250 along the lateral line. 



The typical alpinus (Sailling) exhibits about 200 scales along the lateral line, 

 has twelve rays in the anal fin, and shows a white anterior margin on the paired 

 fins. In these three points the present specimen differs, nor is it like Salvelinus 

 alipes, which has twelve or thirteen rays in the first dorsal fin, 126 scales in the 

 lateral line, according to Dr. Suckley. Giinther regards S. alipes as identical with 

 S. stagnalis. It may be added that the present specimen has the following fin-ray 

 formula : — P. 14, D. lo, V. 11, A. 10, the fins are plain, the dorsum of a dark 

 olive green tint, and the tail truncate or very slightly forked. The weight is from 

 3 lb. to 18 lb. The specimen of caplin is a somewhat diminutive dried example, 

 but a careful examination showed that it differed in no respect from the caplin 

 (Mallotus villosus) which abounds in the Gulf of St. Lawrence. The presence of 

 caplin in Hudson Bay might be taken as an indication that cod occur there. It 

 is the favourite food of the cod at certain seasons. 



The specimen of sturgeon from Hudson Bay is Aeipenser sturio, L., though the 

 specimen is very young, less than six inches in length, and the external features 

 are known to change materially with the attainment of maturity. In young 

 .sturgeon the snout, as a ride, is long and attenuated, the body slender, the enamel 

 plates highly developed, and the spines prominent and hooked. This example has : 

 dorsal plates 14, lateral 35, ventral 11 ; and the fin-rays are : dorsal fin 36, anal 20. 

 These details in other species are as follows : — 



