ANIMALS. 225 
smooth character of the scales, and their large size,—and the limited heterocercism of 
the tail. In referrmg to Agassiz’s description of P. glaphyrus, I find these are the 
principal characters assigned to that species, combined with the dentation of the free 
edges of the scales. The last feature I failed to detect at first sight, in your specimen ; 
but I have since, with a strong light, discovered two or three scales near the head, having 
posterior edges perfect, and showing the dentations. There remains, therefore, no 
doubt on my mind (although the body of the fish is certainly more slender than the 
one figured by Agassiz), that it is a small P. glaphyrus. Judging from Agassiz’s 
figure, I think the belly scales in the York Museum specimen (vide Pl. XXII, fig. 3) 
are a little dislocated downwards, giving a deeper appearance to the body. In the 
Whitley specimen, the dislocation and elongation of the head and shoulders tend to 
convey the idea of more slender proportions than the Fish really possessed. Taking 
these points into consideration, I do not think the discrepancies sufficient to warrant 
the establishment of a new species.” 
This, which is another rare species, occurs in the Marl-slate at Midderidge, 
East Thickley, West Bolden, Houghton-le-Spring, Whitley, Rushyford, Ferry Hill, 
and Thrislington Gap. It has been found, according to Dr. Geinitz, at Mansfeld 
in the Kupferschiefer. 
PALEHONISCUS LONGISSIMUS, Agassiz. Plate XXI, fig. 2 c. 
PALHONISCUS LONGISSIMUS, Agassiz. Poiss. Foss. vol. ii, p. 100, pl. x ¢, fig. 4. 
—_— — Ann. Mag. Nat. Hist., vol. vii, p, 495, 1841. 
— — 4h Morris, Catalogue, p. 201, 1843. 
— —_ Ae Rep. 13th Meet. Brit. Assoc., p. 198, 1844. 
— — ) De Verneuil, Bull. Soc. Géol. de France, 2™ série, 
vol. i, p. 38, 1844. 
— — i Geol. Russ., vol. i, p. 227, 1845. 
— — y Tennant, Strat. List, p. 89, 1847. 
— — rf King, Catalogue, p. 14, 1848. 
= — Be Howse, Trans. T. N. F.C., vol. i, p. 233, 1848. 
This elegant fish, so well characterised by its specific appellation, has been found 
in Marl-slate at Hast Thickley, Midderidge, West Bolden, and Houghton-le-Spring. 
The beautiful specimen figured, and now in the Newcastle Museum, was got out of 
the same bed at Thrislington Gap. The Whitby Museum contains a specimen, 
apparently of this species, which was found by Miss Green of South Shields in the 
Limestone on the coast of Durham, a little north of Marsden. 
PALHONISCUS MACROPTHALMUS, Agassiz. Plate XXII, fig. 2. 
PALEONISCUS MACROPTHALMUS, Agassiz. Poiss. Foss., vol. ii, p. 99, pl. xe, fig. 3. 
— —_ Ann. and Mag. Nat. Hist., vol. vii, p. 495, 
1841. 
= — en Morris, Catalogue, p. 201, 1843. 
dd 
