1 903.] Hay, Cretaceous Fishes from Mount Lebanon, Syria. 443 



In the species before us I find 1 7 vertebral rings in a length 

 of 10 mm. in the larger specimen, and 23 in the same length 

 of the smaller one. The pleurohsemacentra are usually some- 

 what shorter than their companion rings. Both have their 

 neural arches low and extending backward so as to overlap the 

 arch just behind it. The epihypocentra present a short back- 

 wardly directed spine and a shorter process which extends for- 

 ward somewhat over the arch in front. The pleurohaemacentra 

 possess neither process. Both kinds of centra send downward 

 a rather broad, short process, that of the epihypocentrum 

 being apparently somewhat longer. No ribs are found ar- 

 ticulating with any of these processes. Both the pleurohs- 

 macentra and the epihypocentra are constricted about the 

 middle. I have not been able to determine whether or not 

 they permitted the passage of the notochord. 



When we come to examine the caudal region we find the 

 pleurohaemacentra not especially different from those of the 

 abdominal region (PI. xxxvii, Fig. 6). The inferior processes 

 are, however, somewhat smaller. On the other hand, the epi- 

 hypocentra are furnished with well-developed haemal arches. 

 These can be seen to continue to near the tip of the tail. 

 Altogether there are close to 275 vertebral rings preserved 

 in the larger specimen. Of these about 170 belong to the 

 caudal portion of the body. This would indicate that in the 

 tail there are 85 complete vertebrae. 



No traces are seen anywhere of either fin rays or of inter- 

 neural or interhsemal bones. All were probably absent. The 

 extremity of the tail is shown only by a faint impression on 

 the matrix, and there are no traces of a caudal fin. Like- 

 wise, there are no indications anywhere of scales. 



The head of this species appears to be remarkably small. 

 Its length in the smaller specimen, measured to the occiput, 

 is only 4.5 mm.; but, including the branchiostegal rays, 9.5 

 mm. Its height is 1.5 mm. The snout appears to have been 

 conical. In the jaws are small teeth in more than a single 

 row. The branchiostegal rays are slender, much longer than 

 the skull, and the hinder ends are somewhat curved upward. 

 No opercular bones or pectoral arch is present. 



