418 FISHES. 



Eighth Family — NANDiDiE. 



Body oblong, compressed, covered ivith scales. Lateral line 

 interrupted. Dorsal fin formed iy a spinalis and soft portion, 

 the number of spines and rays being nearly equal ; anal fin with 

 three spines, and with the soft portion similar to the soft dorsal. 

 Ventral fins thoracic, with one spine, and five or four rays. 

 Dentition more or less complete, but feeble. 



This small family consists of two very distinct groups. 



A. Plesiopina. Marine fishes of small size, with pseudo- 

 branchise and only four ventral rays. Plesiops from the coral- 

 reefs of the Indo-Pacific, and Trachinops from the coast of 

 N'ew South Wales, belong to this group. 



B. Nandina. Freshwater fishes of small size from the 

 East Indies, without pseudobranchise, and five ventral rays. 

 The genera are Badis, Nandus, and Gatopra, 



Ninth Family — Polycenteid^. 



Body compressed, deep, scaly. Lateral line none. Dorsal 

 and anal fins long, both with numerous spines, the spinous 

 portion being the more developed. Ventrals thcn'acic, with one 

 spine and five soft rays. Teeth feeble. Pseudobranchim 

 hidden. 



Only two genera, each represented by one or two species 

 in the Atlantic rivers of Tropical America, Polycentrus and 

 Monocirrhus, belong to this family. They are small insecti- 

 vorous fishes. 



Tenth Family — Teuthidid^. 



Bodjy oblong, strongly compressed, covered with very small 

 scales. Lateral line continuous. Eye lateral, of moderate size. 

 A single series of cutting incisors in each jaw ; palate tooth- 

 less. One dorsal fin, the spinous portion being the more deve- 



