1903.] Hay^ Cretaceous Fishes from Mount Lebanon, Syria. 4^9 



DERCETID^. 



Leptotrachelus serpentinus, sp. nov. 

 Plate XXXII. Figure i. 



This species is represented in the collection by two speci- 

 mens, No. 451 la (3683), which was collected at Hajula, and 

 No. 45116 (3739). which was obtained at Hakel. The first 

 mentioned specimen is regarded as the type. It lacks a large 

 part of the caudal region and the whole of the head, except 

 a part of the opercular apparatus. The length of the speci- 

 men in its present condition is 260 mm., and the total length 

 in life could hardly have been less than 300 mm., and was 

 probably more. The distance from the opercular region to 

 the ventral fins is 134 mm. The diameter (probably the 

 horizontal) at the ventral fins is contained in the distance 

 from the operculum to these fins thirteen times. In L. 

 triqueter the diameter at the ventral fins, as shown by Pictet 

 and Humbert's figure (Nouv. Rech., pi. xiv, fig. i), is con- 

 tained in the part of the body in front of the ventral fins about 

 seven times. We have in both of these cases apparently the 

 breadth of the body and not its height. L. serpentinus, there- 

 fore, appears to have been a much slenderer fish than L. tri- 

 queter. This slenderness is shown also by the bodies of the 

 vertebrae, which are more than three times as long as the 

 diameters of their articular ends. In L. triqueter the bodies 

 are said to be twice as long as deep. 



There are 3 1 vertebrae between the operculum and the ven- 

 tral fins, about the same number as in L. triqueter. The ver- 

 tebral centra are much constricted. Each vertebra of the 

 abdominal region sends out on each side two long processes, 

 which diverge from the middle of the centrum. The broader 

 one is directed outward and forward. Near its end there is 

 articulated to it the head of a long, slender rib. The posterior 

 and narrower process is directed outward and backward. Its 

 distal end approaches very closely the rib-bearing process of 

 the next vertebra behind. In the region of the ventral fins 

 these processes are nearly 5 mm. long. These lateral pro- 

 cesses are found on about 1 2 of the vertebrae behind the ven- 



