298 A Review of American Diodontidw. 



1. DIODOX. 



Diodon Linnaeus, Syst. Nat., Ed. X, 335, 1758 {atinga, hystrix, etc.). 

 ? Trichodiodon Bleeker, " Atl. Ichth. Gymnod., 49," 1865 (pllosu.s). 

 Paradiodon Bleeker, "Atl. Ichth. Gymnod., 56, plate 3, fig, 2," 1865 

 (hystrix). 



The genus Trichodiodon is based on a description by Mitchill, 

 of a species which has not been since recognized. It is not un- 

 likely that it is simply the very young of Diodon hystrix. At 

 any rate, its place in the system needs verification. 



The name Paradiodon is the result of Bleeker's rule of always 

 regarding the first species mentioned in any new genus as the 

 type of the genus. In this case, atinga is the first species men- 

 tioned under Diodon by Linnaeus, and this atinga is a species of 

 Ohilomycterus. 



ANALYSIS OF THE SPECIES OF DIODON. 



a. Spines terete. - - - Hystrix, 1. 



b. Frontal spines not as long as post-pectoral spines (in adults not half as 

 long, about as long as eye) ; pre-dorsal spines very short, three- 

 rooted, fixed or nearly so ; 20 spines in a series between snout and 

 dorsal ; post-pectoral spines very much elongate ; dorsal rays, 15 ; 

 anal, 15 ; upper lobe of pectorals little longer than lower. Adult 

 above everywhere spotted with round black spots ; these are largest 

 in front of dorsal, smallest on naked area about mouth ; white be 

 low ; young with large dark blotches, the coloration precisely siini 

 lar to that of holacanthus. - ... y a r. Hystrix. 

 bb. Frontal spines longer than post-pectoral spines, about twice as long as 

 eye; pre-dorsal spines not shortened, two-rooted, erectile; 14 to 17 

 spines in a series between snout and dorsal ; post-pectoral spines 

 not especially elongate ; dorsal rays, 12 ; anal, 12 ; pectoral broader 

 than long, upper lobe pointed, lower lobe rounded. A broad black 

 bar from eye to eye, continued below the eye as a narrow bar ; a 

 broad bar across occiput ; a black blotch above each pectoral ; a 

 short bar in front of dorsal ; another in which the dorsal is inserted ; 

 a blotch behind the pectoral, and many small spots and blotches on 

 the upper parts. Var. jIolacanthus. 



aa. ' ' Spines compressed laterally, short ; 15 spines in a series between snout 

 and dorsal ; upper parts covered with round spots ; those about 

 pectorals sometimes confluent into a blotch ; fins immaculate." 



Maculifer, 2 



