43 6 Bulletin American Museum of Natural History. [Vol. XIX, 



ruptedly through the vertebral centra. The neural spines of 

 the caudal region are moderately stout and are smaller at 

 their bases than in the middle of their length. The haemal 

 spines are slender and tapering, and have long, delicate flesh- 

 bones attached to them. 



No. 45156 (3762) appears to have only 40 or 41 vertebrae in 

 front of the anal fin. In No. 4515c (3695) we have what 

 seem to be the most anterior rays of the dorsal fin, and these 

 are placed over the 12th vertebra behind the occiput. An- 

 other specimen confirms this view. 



No. 45i5<i (3790), from Hakel, probably belongs to this 

 species, since it is too large to belong to U . hakelensis. This 

 presents the vertebral column seen from above. In the case 

 of some of the vertebras the neural arches have slipped to one 

 side of their centra, so that the upper surfaces of the latter 

 are exposed. The right and left portions of each arch are dis- 

 tinct, never having been co-ossified (PL xxxvii. Fig. 7). 



No. 45i5(? (3860) presents the head and the trunk to a 

 short distance behind the origin of the anal fin. Here also 

 there are 43 vertebrae in front of the anal. The head is flat- 

 tened from above, and its hinder portion is broken away. 

 Numerous short blunt teeth are seen on the dentary and the 

 maxilla. There are also traces of vomerine teeth. Eleven 

 branchiostegal rays are counted on one side. They extend 

 far backward and the distal ends of some are curved up- 

 ward. Both pectoral fins are displayed, and each seems to 

 have possessed at least 20 rays. There are no traces of ven- 

 tral fins, although the conditions seem favorable for their pre- 

 servation had the}^ existed. 



ANGUILLAVID^, fam. nov. 



Apodes with well-developed cleithrum, pectoral arch, pec- 

 toral and ventral fins, and a distinct caudal fin. Dorsal and 

 anal fins extended. Palatopterygoid arch developed. Scales 

 rudimentary or absent ; in some cases a row of enlarged plates 

 on each side, probably on the lateral lines. Ribs present. 

 One genus, Anguillavus. 



