842 FISHES — CYPRINIDJE. 



shovel-like mandible would appear to be adapted for removing these 

 creatures from their hold on the rocks and bottom, while the great 

 strength of the pharyngeal walls and muscles enables the fish to crush 

 the shells before mastication with the pharyngeal teeth." It takes the 

 hook readily, and is therefore a " boy's fish." 



Genus 31. HUDSONIOS. Girard. 



Sudsonius, Girard, Proo. Acad. Nat. Sci. Phila., 1856, 210. 

 Hi/hopsia, Cope, Trans. Am. Philoa. Soc, 1866, 385 (not of Agassiz). 

 Phoiogenis, Copk, Trans. Am. Philos. Soc, 1866, 379 (in part). 



Type, Clupea hvAeonia, DeWitt Clinton. 



Etymology, Hudson Kiver. 



Body oblong or elongate; month rather small, horizontal or somewhat oblique; jaws 

 normal; no barbels; teeth 4 4 or 1, 4 4, 1 (in one species 1, 4-4, 2), hooked, with grind- 

 ing surface ; scales large ; lateral line complete ; dorsal fin inserted nearly over ven- 

 trals; anal fin short. A very large genus including our smallest and feeblest minnows, 

 together with some of our largest species. 



This genus, as now nnderstood, comprises three well marked subgenera, which have 

 under one name or another been sometimes taken as genera. These are : 



1. Hudsonius proper, including silvery species of large size, with short heads ; dorsal 

 fln inserted in front of the ventrala ; teeth two- rowed ; scales not closely imbrica'ed ; 

 fins plain. These species bear a close resemblance to Hybognathus. 



2. Miniellus (^Jordan), including small, plain species, with rather large head ; dorsal 

 fin inserted over ventrals ; teeth one-rowed ; scales large, not closely imbricated ; fins 

 plain. These are the smallest and most insignificant of American Cyprinidse, and may 

 be usually known from the young of larger species by the large scales before the dorsal. 



3. Photogenis (Cope), including species of moderate size; compressed; dorsal fin in- 

 serted behind the base of the ventrals : teeth two-rowed ; scales deeper than long, 

 closely imbricated ; dorsal fin wilh a dark blotch on its upper posterior portion ; males 

 in spring with the snout, etc., tuberculate, and the fins charged with satin-white pig- 

 ment. The members of this group closely resemble certains forms referred to Cliola, and 

 in some degree certain species of Luxilus. Besides the following, several other southern 

 and western species perhaps occur within our limits. 



Analysis op Spkcibs op Hudsonius. 



* No black blotch on posterior rays of dorsal ; dorsal not inserted behind ventrals ; scales 

 not closely imbricated, 

 t Head short, about 4J in length. .... storbrianus. 



tt Head comparatively long ; 3J to 4 in length. 

 a. Mouth inferior, horizontal. 



6. Lateral line 34 ; pectorals reaching ventrals. . . . volucellus. 



}>}>. Lateral line 36 ; head stoutish ; peotorals short. . . stramineus. 

 aa. Mouth terminal, oblique. 

 0. Lateral line 35. ...... pretensis. 



CO. Lateral line 44. ..... . hjematurus. 



*' A black blotch ou posterior rays of dorsal ; dorsal inserted behind ventrals; scales 

 deeper than long, closely imbricated. .... analostanus. 



