L. M. Lambe — Fish Fauna of the Albert Shales. 171 



Eloniciithys ellsi sp nov. 



A species of small size. Type and only specimen known 

 about 12 cm (If inches long). Greatest depth a little less, 

 than one-fourth the length. Head, with opercular apparatus, 

 one-fourth the total length. Dorsal tin large, arising very 

 slightly behind the mid-length of the fish, and but little in 

 advance of the anal fin, which is about the size of the dorsal. 

 Both of these fins are triangular, with a base about equal to 

 the length of the anterior border. Fulcra are apparently 

 present on all the fins ; plainly seen on the dorsal and anal 

 fins. Of the ventral and pectoral fins, a few rays only are 

 preserved, which serve as an index to the fins' position. Ven- 

 tral fins rather closer to the anal than to the pectoral fins. The 

 fin-rays are articulated, except the principal ones of the pecto- 

 ral fins, which are entire, at least, pro xim ally ; they are finely 

 striated in the direction of their length. The tail is deeply 

 forked. Scales of moderate size ; about as deep as broad on 

 the flank anteriorly, figure 5, where they are ornamented with 

 nine or ten conspicuous, narrow ridges, directed backward and 

 deeply serrating the posterior border. Posterior flank scales, 

 figure 6, less highly ornate, and with few but well-marked 

 serrations posteriorly. Scales of the caudal body prolongation 

 nearly smooth. Enlarged scales extend along the dorsal ridge 

 in a row, in advance of the dorsal fin, to the head, and behind 

 the same fin backward to the termination of the upper lobe of 

 the tail. Similarly enlarged scales occur between the anal fin 

 and the lower lobe of the tail, with a few, probably three or 

 four, in front of the anal fin. Head-bones marked by irregu- 

 lar, short ridges, and tubercles. Suspensorium apparently 

 oblique. 



The ridges of enamel on the anterior flank scales constitute 

 the most conspicuous feature of the scale ornamentation of this 

 species. These ridges, nine or ten in number, are mainly 

 developed on the posterior half of the scale, and have the 

 appearance of rows of connected tubercles. A few fine striee 

 occur near and parallel to the lower margin of the scales. 



The enlarged ridge scales are rugosely and irregularly 

 striated longitudinally, and are toothed behind. Conspicuous 

 horizontal striations or linear depressions occur in the modified 

 scales of the caudal ridge. 



The most distinctive character of the species is the style of 

 ornamentation of the anterior flank scales, which is different 

 from that of any other of the Albert shales fishes, and, so far 

 as the writer is aware, from that of any species of the 

 Palseoniscidse. 



The species is named after Dr. R. W. Ells, to whom we are 

 indebted for the one and only specimen known. This speci- 

 men constitutes the type of the species. 



