HAL0SAURIDJ5. 
163 
account of tho osteology and the anatomy of some of the soft parts 
of tho type genus is given by Giinther 
Genus ECHIDNOCEPHALUS, W. von der Marck. 
[Zeitschr. deutsch. geol. Gcsell. vol. x. 1858, p. 247.] 
An imperfectly known fish from which the existing genus Ualo- 
saurus is not yet clearly distinguished. Tho dentition, cheek-plates, 
and pectoral fin are unknown, while the number of rays in the 
dorsal and pelvic fins is slightly less than is usual in the recent 
genus. Branchiostegal rays about 12 in number. Vertebral centra 
Tery short and numerous as far as the middle of the caudal region, 
marked with delicate longitudinal striae. Dorsal fin with two 
K i triple, and about six branched rays, arising behind the pelvic pair 
a nd in advance of the anal, which is much extended and not 
differentiated from the caudal. Scales of lateral line thickened and 
apparently enlarged. 
Echidnocephalus troscheli, V . von der Marck. 
18o8. Echidnocephalus troschelU , W. von der Marck, Zeitschr. deutsch. 
geol. Gesell. vol. x. p. 247. 
1858. Echidnocephalus temiicaudus , W. von der Marcx, ibid. p. 248. 
[Imperfect fish ; Academy of Minister.] 
1863. Echidnocephalus troscheli , W. von der Marck, Palseontogu vol. xi. 
P- 65, pi. viii. fig. 1. 
1863. Echidnocephalus tenuicaudus, W. von der Marck, ibid. p. 5b, 
pi. viii. figs. 2, 3, pi. xiv. fig. 1. 
1868. Eehidnocephalus troscheli , IV, von der Marck, loc. cit. vol. x\ . 
p. 288. 
1873. Echidnocephalus troscheli, W. vender Marck, loc. eif.vol.xxii.p4J2. 
1897. Echidnocephalus troscheli, A. S. Woodward, Proc. Zool. fiioc. 
p. 268, pi. xviii. 
Type. Imperfect distorted fish ; Academy of Miinster. 
The type species, attaining a length of about 0'3> Length of 
head with opercular apparatus apparently twice as great as the 
maximum depth of the trunk, and equal to the distance Detween 
the clavicle and pelvic fins. Vertebral column as far as the middle 
°f the caudal region comprising eighty short and deep contra ; 
those beyond being relatively longer and less ossified. Pelvic tins, 
each with about 6 rays, arising midway between thepectoral arch and 
Lhe anal fin ; dorsal fin short and deep, arising nearly opposite the 
1 A. Giinther, Deep Sea Fishes, • Challenger ’ Hep— Zool. vol. xxii. (1887), 
P- 232, pi. lx, fig S , i_8. 
M 2 
