NO. 4 MYERS AND WADE : NEW GENERA AND SPECIES OF EELS 69 



Measurements of holotype in mm. — Length 99, head and trunk 41, 

 tail 58, head 14, snout 3, eye 2.5, cleft of mouth 3.5, depth 6, pectorals 5, 

 gill openings 2.5, isthmus 2. 



Description. — Body elongate, cylindrical except the last fourth of 

 tail, which becomes somewhat compressed. Body heavier at middle than 

 anteriorly. Head and trunk 1.42 in tail. Head 2.92 in head and trunk, 

 7.07 in total length; its greatest depth slightly less than greatest depth of 

 body. Eye 1.2 in snout and 5.6 in head. Snout 4.66 in head. Cleft of 

 mouth 4 in head, not quite reaching below center of eye. Body depth 

 greatest at midpoint of total length, into which the depth goes 16.5 times. 

 Isthmus slightly narrower than height of gill openings, which are equal 

 to eye. Pectorals long and narrow, well developed, 2.8 in head. Dorsal fin 

 inserted over gill openings, low anteriorly, becoming higher on tail. Anal 

 fin about equal in height to dorsal. Both fins confluent around tip of tail. 

 Gill openings low on sides, vertical, top of slit not reaching the upper 

 edge of the narrow pectoral base. 



Anterior nostrils tubular, just above edge of upper lip, near tip of 

 snout. Posterior nostril just in front of eye, but not in contact with it, and 

 at the level of the lower edge of the pupil ; it is elongated and has a very 

 slightly raised rim. Maxillary teeth in one irregular series, the teeth small, 

 pointed, slender, depressible, and irregularly placed, slightly larger and 

 more recurved anteriorly. Maxillary teeth continued around tip of jaw, 

 and somewhat enlarged. Vomerine teeth in a small patch of 6 to 8 teeth 

 at the head of the shaft ; behind this there is a short irregular row of small 

 teeth on the shaft. Mandibular teeth similar to maxillary teeth in size and 

 shape, disposed in a narrow band, narrowing posteriorly to a single row, 

 and widening anteriorly into three irregular rows. 



Color veiy light cream, with no dark markings on the body, except 

 minute black specks dorsally, which are visible only under the microscope. 



From Ariosoma gilberti, the only other known species from eastern 

 tropical Pacific, vomerina differs in having the maxillary teeth uniserial 

 and not in a villiform band. In vomerina there are 6 to 8 teeth at the head 

 of the shaft of the vomer, followed by 3 to 4 small teeth on the shaft, 

 while in gilberti the vomerine teeth are arranged in an elongate triangular 

 patch with a long posterior projection. In vomerina the tail is longer than 

 the rest of the body by a length greater than the head, while in gilberti 

 the tail is only the length of the snout longer than the rest of the body. 

 Vomerina also differs from gilberti in having the isthmus narrower than 

 the gill openings, instead of much wider. 



