52 
ACTIN' OPIEETGrII. 
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Type. Imperfect fish ; Newcastle-upon-Tyne Museum. %- 
The type species, attaining a length of about 0-09. Head with 
opercular apparatus occupying slightly less than one-quarter of the 
total length: maximum depth of trunk equalling about twice that 
of the caudal pedicle, and comprised four times in the total length. 
Head and opercular bones faintly rugose; operculum broader than 
deep. Dorsal fin with about 10, and anal with 8 rays. Scales 
unornamented, not serrated. 
Form. Loc. Upper Permian (Magnesian Limestone): Durham. 
wv 
\A' 
36388-90. Two typical specimens, the first wanting the extremity 
of the snout and the paired fins, the second more imper¬ 
fect ; also a smaller fish; Pulwell Hill, near Sunderland. 
Presented by Sir Hedworth Williamson , Bart., 1862. 
P. 3481 a, b. Two fine specimens about 0'09 in length, somewhat 
fractured, but showing parts of all the fins; Pulwell Hill. 
In the second specimen the scales are distinctly shown to 
be smooth. Enniskillen Coll. 
P. 3481 C. Slightly smaller fish displaying portions of the median 
fins ; Pulwell Hill. Enniskillen Coll. 
P. 3481, P. 3483, P. 4342. Four more imperfect specimens, three 
being much smaller than the preceding; Pulwell Hill. 
One of the two specimens occurring on a single slab 
appears to exhibit traces of styliform teeth in the dentary, 
and enlarged anal scales in advance of the median fin. 
Enniskillen Coll. 
P. 1032. Pish about 0065 in length and two smaller more im¬ 
perfect specimens ; Pulwell Hill. Egerton Coll. 
P. 1032 a. The hinder abdominal and caudal region of two asso¬ 
ciated individuals ; Pulwell Hill. The dorsal ridge-scales 
are shown to he relatively large, hut not acuminate. 
Egerton Coll. 
44210. Small well-preserved fish, wanting the extremity of the 
head and tail; Pulwell Hill. Purchased , 1873. 
Acentrophorus abbsi (Kirkby). 
1862. Palceoniscus abbsii, J. W. Kirkhv, Ann. Mag. Nat. Hist. [31 
vol. ix. p. 268. 
1864. Palceoniscus abbsii, J.W. Kirkby, Quart. Journ. Geol. Soc. vol. xx. 
p. 355, pi. xviii. fig. 3. 
1877 Acentrophorus abbsii, K. H. Traquair, Quart. Journ. Geol. Soc. 
vol. xxxiii. p. 565. 
