316 
actino pier yen. 
the total length of the fish. External head- and opercular bones 
and postelavicnlar scales ornamented with conspicuous coarse rugae 
and tuberculations. Some of the principal scales of the anterior 
series on the flank nearly twice as deep as broad, and those of other 
series also more or less deepened; most of the scales of the 
abdominal region conspicuously serrated, some of those of the 
caudal region with a few widely-separated posterior denticles. 
Form. § Loc. Upper Trias : North Italy. 
P. 1548. Fish wanting head and having part of the ventral squama- 
tion displaced ; Perledo, Lake of Como. Egerton Coll. 
Allolepidotus dorsalis (Kner). 
(?) 1833-44. Pholidophorus dorsalis, L. Agassiz, Poiss. Foss. vol. ii. pt. i. 
pp. 9, 287 (inadequately defined). 
1866. Pholidophorus dorsalis , R. Kner, Sitzungsb. k. Akad. Wiss., 
math.-naturw. Cl. vol. liv. pt. i. p. 324, pi. vi. fig. 1. 
1866. Semionotus striatus , R. Kner {errore), ibid. p. 322, pi. v. fig. 1. 
1867. Semio7iotus striatus, R. Kner ( errore ), loc. cit. vol. lvi. pt. i. p. 898, 
pi. i. fig. 1. 
1867. Pholidophorus dorsalis, R. Kner, ibid. p. 903, pi. ii. fig. 2. 
Type. Imperfect trunk. 
A robust species, attaining a length of about 0T4. Length of 
head with opercular apparatus nearly equalling the maximum 
depth of the trunk and contained less than four times in the total 
length of the fish. External head- and opercular bones feebly 
ornamented with coarse rugae and tuberculations. None of the 
scales much deeper than broad; few of those of the abdominal 
region serrated, nearly all non-serrated and smooth. 
Form. Sf Loc. Upper Trias : Tyrol. 
21380. Fish wanting head and extremity of caudal fin, but with 
well-preserved squamation ; Seefeld. Purchased , 1847. 
P. 1544. A more imperfectly preserved specimen, showing the 
caudal fin ; Seefeld. Egerton Coll. 
16655. A smaller imperfect fish, with some well-preserved scales ; 
Seefeld. _ _ Purchased. 
p UV O sfjppy/>.£~y 
Genus PTYCHOLEPIS, Agassiz. 
[Neues Jahrb. 1832, p. 142.] 
Trunk elegantly fusiform. Snout acutely pointed and prominent ; 
external head-bones and opercular bones ornamented with prominent 
ridges of ganoine: marginal teeth comparatively small and stout, 
