454 Zoological Society. 



the author to be one of those species whose natural position is 

 difficult to ascertain, from their partaking of the characters of se- 

 veral different groups. Viewed as the type of a new genus, Nema- 

 dactylus may be characterized as having none of the bones of the 

 gill-cover armed or sculptured, the operculum itself being destitute 

 of projecting points, but as differing from any described sparoid 

 form in having simple inferior pectoral rays, one of them projecting 

 beyond the rest, as in Cheilodactylus, and in the teeth, which are 

 minute and slender, in a single row on the jaws. The palate, vomer, 

 tongue, and pharyngeal parietes are toothless. The fins are scale- 

 less, the dorsal single, the branchial rays only three in number, the 

 scales cycloid, and the pyloric caeca few (three). There is but one 

 specimen of Nemadactylus concinnus in the collection, which is three 

 inches and a half long, has a compressed elliptical form, and a spar- 

 oid aspect. Its lateral line is marked by a series of bright thin 

 scales, and beneath it, the integuments are merely silvery with 

 wrinkles, as in some scomberoid fishes ; but the specimen has been 

 long in spirits with other fish, and it is possible that the scales of 

 the flanks may have been detached. If they actually existed, they 

 must have been proportionally larger than those on the back, jud- 

 ging from the wrinkles of the epidermis. The scales of the back and 

 top of the head are small, thin, and delicate, like those of a mackerel. 

 Vertebrae 34. 



It may be thus characterized : — 



Nemadactylus, n. g. 



Piscis acanthopterygius. Operculum las ve, inerme. Vinnce esquamosae, 

 pinna dorsalis unica : radii pinnae pectoralis inferiores (sex) sim- 

 plices, quorum unus productus. Cos tee branchiostegce paucae (tres) . 



Intermaxillarum pediculi breves. Dentes gracillimi minuti in ambitu 

 oris tantum positi. Fauces palatum et lingua glabri. Squamce 

 tenerae, laeves, infraque lineam lateralem scomberoideae. Cceca 

 pylorica pauca (tria). 



N. concinnus, species unica adhuc cognita. 



Radii:— Br. 3-3; P. 9 et 6 ; V. 1, b ; D. 17, 28; A. 3, 15; 

 C. 15£. 



10. Latris Hecateia is the appellation given by the author to the 

 type of another annectant genus, which he considers as taking its 

 position most naturally among the Mcenoidece, but as having many 

 characters in common with a percoid group composed of the genera 

 Therapon, Datnia, Pelates, Helotes, and Nandus. In Latris the mouth 

 is moderately protractile, the dentition is similar to that of Mcena 

 vomerina, there is a scaly groove for the reception of the deeply 

 notched dorsal as in Gerres, which genus it further resembles in its 



