12. GERRES. 347 



a. Adult. Bahia. Piu-chased of M. Paiziidaki. 



b. Adult. Bahia. Purchased of M. Parzudaki. 



c. Adult : skeleton. Bahia. Piu'chased of M. Parzudaki. 



d. Half-grown. S. Domingo. Piu-chased of Mr. Cuming. 



e. f. Young. Jamaica. From Mr. Gosse's Collection. 

 </. Adult. From the Haslar Collection. 



h. Young. 



i, k. Half-grown and j^oung : skins. 



Skeleton. — The vciy remarkable form of the fii'st interhaemal spine 

 has been mentioned by Cuvier. He states the number of the caudal 

 vertebrae to be thirteen ; but I have found fifteen, as in other species 

 of Gerres. The length of the abdominal portion of the vertebral 

 column is to that of the caudal as 1 : l-(3. 



11. Gerres nigri. (Plate XX. fig. B.) 

 D. ^. A.|. L. lat. 42. L. transv. 5/11. 



The height of the body is 2|- in the total length (without caudal 

 fin) ; the diameter of the eye is about one-third of the length of the 

 head, rather longer than the snout, and equal to the distance between 

 the eyes. The groove for the processes of the intermaxillary bones 

 is elongate, triangular, reaching nearly to the vertical from the 

 centre of the eye, and is entirely scaleless. Spines of the fins rather 

 slender ; the second of the dorsal is 2^ in the height of the body, and 

 nearly twice as long as the tliird of the anal, which is rather longer, 

 but less stout, than the preceding. Silvery, with indistinct longitu- 

 dinal stripes above the lateral line ; the vertical fins blackish ; dorsal 

 black-edged. 



Mouth of the River Niger. 



a. Adid.t. River Niger. From Mr. Fraser's Collection. 



b. Half-grown. Coast of Africa. From the Haslar Collection. 



Description. — The body is moderately elevated, its greatest depth 

 being below the origin of the dorsal, where it is contained 2i in the 

 total length, without caudal fin, or 3^ in the same length, the caudal 

 included. The upper profile anteriorly and posteriorly descends aa 

 much as the lower ascends, and they meet in front at an acute 

 angle. The length of the head is 3|^ in the total, without caudal 

 tin. The snout is rather shorter than the diameter of the eye, the 

 upper maxillary extending to the anterior margin of the eye. The 

 groove for the processes of the intermaxillary bones is elongate, 

 triangidar, with a somewhat rounded posterior angle, and widening 

 anteriorly. The scales of the upper siu'face of the skull do not extend 

 over that groove, forming a stripe between the groove and the 

 orbit, and terminating behind the nostrils, wliich are situated high up 

 the sides, nearly halfway between the orbit and the end of the snout. 

 The pra^orbital is entirely scaleless : auti'i'iorly broad, it is narrowest 

 between tlic maxillary and the orbit. The scales of the cheeks are 

 smaller than those of the body, and extend in a narrow stripe on the 

 mandibula, immediately behind the maxillary. The imeoperculum is 



