Davis—On the Fossil Fishes of the Chalk of Mount Lebanon. 475 
very small, are more or less conical and acutely pointed. The lower jaws were 
deep and strong. 
This species appears to fall naturally into the Family Scylliide of Giinther. 
The discovery of these specimens adds a second member of the family to the 
one in the Museum at Geneva, already described by Messrs. Pictet and Humbert 
(‘‘ Nouvelles Recherches sur les Poissons fossiles du Mont Liban., 1866,” p. 111, 
pl. xvut., figs. 2-4) as Scyllium Sahel Almez. The total length of this specimen 
was estimated at 10 centimetres (4 inches); the mouth and teeth were similar 
to the species now described. The two fishes differ essentially in the position 
of the fins and the proportionate number of vertebra. In this species the 
first dorsal fin is situated above the forty-second and forty-third vertebrae, whilst 
in Scyllium Sahel Almez it is over the twenty-seventh; the commencement of 
the ventral fins in the latter is opposite to the twentieth vertebra, in the 
former they are opposite to the twenty-ninth. The specimens now described 
are much longer, in proportion to their size in other respects, than those of 
MM. Pictet and Humbert. 
Locality and Formation—Upper Cretaceous: Sahel Alma, Mount Lebanon, 
£x coll.—Robert Damon, Esq., Weymouth. 
Thyellina curtirostris, Davis. 
(Rl xyes, fio: 1) 
The specimen which serves for the following description is well preserved, 
and exhibits the ventral surface of the fish. The head is characterized by its 
short rounded snout, somewhat similar to Spinax primzvus; but, unlike that 
genus, it has no spines attached to the dorsal fins. The length of the fish 
preserved is 11°5 inches; some portion of the extremity of the tail is missing. 
The head to the base of the pectoral fins occupies 2:4 inches. 
The spinal column consists of more than a hundred vertebre ; those of the 
extremity of the tail, being somewhat displaced, cannot be exactly identified. 
They are 0:1 of an inch in length, and about the same height anteriorly ; on 
the median part of the column the vertebre are 0°15 of an inch in length; 
towards the caudal extremity they become gradually smaller and narrow in 
proportion to the height. 
The head is large; the snout extends 0°6 inch beyond the mouth; it is 
rounded, and probably flattened. The jaws extend 1:1 inches backwards, and 
and are 0°8 of an inch wide posteriorly; they are furnished with a large number 
of small sub-conical teeth, longer and more attenuated in the anterior part of 
the mouth. Between the posterior extremity of the jaws and the pectoral fins 
there is a series of five branchiostegal rays. 
