170 L. M. Lambe—Fish Fauna of the Albert Shales. 



scales extend in a row from near the head to the dorsal fin, 

 and from the latter to the extremity of the tail, on the upper 

 lobe of which they are of modified shape and gradually dimin- 

 ishing size. Between the anal fin and the tail similar scales 

 occur. Enlarged, longitudinally striated scales are seen in a 

 number of specimens, between the anal and ventral fins. 

 The more anterior dorsal ridge scales are ovate, slightly longer 

 than broad, becoming more pointed behind on approaching 

 the dorsal fin. The posterior margin is denticulated. 



In the fins, the rays are articulated throughout except the 

 most proximal part of the first two or three rays of the pecto- 

 ral. They subdivide distally, and a second and apparently 

 also a third subdivision may take place, On the front border 

 of the joints, in the more anterior part of the fins, short 

 oblique striations are observed. These particular markings are 

 not observed in the posterior half of the fins, where another 

 style of ornamentation is developed near the base, viz., a 

 minute serration of the hinder border of the joints. 



The mandibular suspensorium is apparently oblique. The 

 teeth, as seen imperfectly in one specimen only, seem to be 

 arranged in two rows, after the manner of the genus, viz., with 

 small teeth in an outer row, and larger ones, at intervals, 

 forming an inner row. 



The type specimen of Dawson's Palceoniscus jacksoni (figure 

 4 of Jackson's plate I) is not available for study, but judging 

 from the figure, and from Dr. Jackson's remarks on its scale 

 ornamentation, it appears to the w T riter probable that it is not 

 distant from F. hroivni. A specimen from McGill Univer- 

 sity museum, labelled P. jacksoni^ Hillsborough, No. 2698, has 

 the scale sculpture and the ornamentation of the joints of the 

 fin rays such as are seen in Jackson's type of F. hrowni with 

 which it is evidently conspecific. Among the specimens from 

 the Natural History Society of New Brunswick is the original 

 of the one from which the plaster cast, mentioned by Sir 

 William Dawson in his Acadian Geology, was taken, wdiich 

 cast formed part of the material on which P. jacksoni was 

 based. The specimen consists of the posterior part of the fish, 

 from slightly in advance of the dorsal fin backward to the end 

 of the tail. The anterior basal portion only of the anal fin is 

 preserved, and the position of the dorsal fin is indicated, but 

 the specimen is elongated by distortion, and both fins are more 

 distant from the tail than they otherwise would be. The gen- 

 eral contour of the specimen is much the same as that of others 

 in the collections of the Survey similarly distorted, and the 

 characters of the scales are clearly those of F. ~browni, to 

 which species the specimen is referred. 



