456 BE VISION OF HETEROMI—aOODE AND BEAN. 



All tlielieteromous teleo.sts have. a siibfusiform, moderately compressed 

 body, with head and snout protriuliiig, and sometimes produced and 

 proboscis-like as in Polyacanthonotus. 



Family i^ o T A C A n T H i d A E . 



Notacantini, Ra.finesque, Iiulice d'lttiologia Siciliana, 1810, p. 34. 

 Notacanthini, Bonaparte, Cat. Metodioo, 1846, p. 72. 

 Notacanthoidei, Bleeker, /. c. 



NoiacauthijGv^TaFAi, Cat. Fish. Brit. Mus., iii, 1861, p. 544. 

 Notacanthida', Gill, Arr. Fam Fish., 1872, p. 21; .Johnson's Cyclopi(?dia, in, 1883, 

 Century Dictionary, iv, 4022.— Jordan and (iiLBEiM, Bull., U. S. Nat. Mus., 

 XVI, p. 370. 

 Heteromous teleosts, with elongate, subfnsiform, moderately com- 

 pressed body. Head short and snout protruding, sometimes produced, 

 proboscis-like (as in Polyavaaihonotus). Mouth moderate, horizontal, or 

 inferior, suctorial (as in Macdonaldia). Scales small on body and head; 

 lateral line present. Teeth slender, closely set, in a single series iu 

 each jaw. G-ill-openings wide, the membranes separate and free from 

 the isthmus. 



Dorsal fin median, with short and free dorsal spines, and with soft 

 rays very few or absent. Anal fin long, rather high, extending from 

 the middle of the body to the caudal, with which it unites, and with 

 numerous spinous rays. Ventrals abdominal, often confluent, with 1-5 

 spines and 4-8 soft rays. Pectorals short and high. Pseudobranchi.ne, 

 none. 



The elaborate anatomical description of Xotacanthus se,vspinis given 

 by Giinther* Avith numerous excellent figures, applies in its general 

 features to all the members of this family. 



In the discussion of the genera and species below, little attention has 

 been given to the degree of connection of the ventral fins. In every 

 instance these are connate or confluent, but the degree of connection 

 depends not so much upon their j^roximity to each other as upon the 

 extent of the connecting membrane in the several forms, and we ques- 

 tion whether the character can be so defined as to serve even for 

 specific distinctions. 



All the species examined by us have the peculiar modification of the 

 posterior extremities of the maxillary, and the sharp spine more or less 

 hidden by the fleshy fold of the lips at the angle of the mouth on either 

 side. 



KEY TO THE GENERA OF NOTACANTIIIIXE AND LIPOGENYID.E. 



I. .Taws normal. Dorsal spines separated. Teeth in both Jaws. 



A. Dorsal spines 6-12. Teeth in upper jaw compressed, and obliquely triangu- 

 lar. Ventrals connate or confluent Notacanthid/E. 



1. Origin of spinous dorsal far in advance of vent. Mouth lateral. Ventral 



fins connate or confluent Notacanthus. 



2. Origin of spinous dorsal in vertical from vent. Mouth subinferior, cres- 



ceutic. Jaws each with 22 teetlu Ventral fms united Gigliolia. 



* ChaUeuijer Report, xxii, p. 243-8. 



