BEKYCin.H. 
387 
Genus SPHENOCEPHALUS, Agassiz. 
[Poiss. Foss. vol. iv. 1838, p. 4.] 
Trunk elongated and laterally compressed. Cleft of mouth little 
oblique, and jaws with very minute teeth. External bones more or 
less ornamented with rows of tubercles. Vertebra about 12 in the 
abdominal, 16 to 18 in the caudal region. Pelvic fins with one 
large, longitudinally ridged spine and 7 soft rays, which are both 
articulated and divided; these fins inserted slightly behind the 
origin of the pectoral pair. Dorsal and anal fins about as long as 
^eep, each with 4 stout, longitudinally ridged spines gradually 
increasing in length, and closely pressed together; caudal fin 
moderately cleft. Scales ctenoid, of moderate size, more or less 
ornamented with granulations ; one series enlarged along the course 
°f the lateral line. 
Sphenocephalus fissicaudus, Agassiz. 
1848-39. Sphenocephalus fissicaudus, L. Agassiz, Poiss. Foss. vol. iv. 
Pp. 4, 129, pi. xvii. figs. 3-5. 
1858. Sphenocephalus Jissicaudus, W. von der Marck, Zeitschr. deutsch. 
geol. Ges. vol. x. p. 253. 
1863. Sphenocephalus fissicaudus , W. von der Marck, Palaeontogr. 
vol. xi. p. 17, pi. iii. fig. 2. 
Type. Nearly complete fish ; Palaeontological Museum, Munich. 
The type species, attaining a length of about 0 - 25. Length of 
head with opercular apparatus about equal to the maximum depth 
°f the trunk and contained somewhat less than twice in the length 
from the pectoral arch to the base of the caudal fin. Dorsal fin 
with 10 or 11 divided rays, completely in advance of the anal, 
which comprises 9 similar rays. 
The squamation noted in the generic diagnosis has not been 
clearly observed in this species. 
Form. Sf Loc. Upper Cretaceous : W estphalia. 
P- 9059. Imperfect large fish originally about 0'23 in length; 
Baumberg. Purchased, 1899 . 
P. 8772-74. Three imperfect specimens, the first unusually large 
and much distorted by crushing ; Baumberg. 
Purchased , 1897. 
P- 3932. Imperfect fish about 0-12 in length, also distorted ; 
Baumberg. Enniskillen Coll. 
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