762 FISHES — ORDERS OF 



anal fins are conjposed of soft rays only, there are at the anterior edgs of the fin, from 

 one to three uudaToloped or radimentary rays, nsually closely adherent to the first 

 developed ray. Some writers enumerate these in their desoriptiions, but in the present 

 memoir they are not counted except in a few cases, where the fac*; is specified. The 

 short spines should, however, never be omittad. The last ray of the dorsal and anal 

 fins is usaally split to the base. This is counted as one not as two. 



In certain fi .bes, as the Trout and Cat fish, there is on the median line of the back 

 behind the doroal fin a fleshy expansion known as the adipose fin. It has of course, no 

 rays, and is not strictly a fin. 



In the present paper the number of spines is indicated by the use of Roman figures; 

 the number of soft rays, by Arabic figures. When a tin has both spines and soft rays, 

 if the two kinds are united by a membrane, a comma (,) separates the number of spines 

 -from the number of soft rays. In case the spines are separated as a distinct fin a 

 dash (— ) divides the two in the enumeration. Thus, in the Black Bass, " D. X,13" 

 indicates a continuous dorsal fin, with ten spines and thirteen soft rays. In the White 

 Bass, "D. IX — 1,12" indicates two dorsals, whereof the first has nine spines, the second 

 has one spine and twelve short rays. 



The number of rays in the pectoral and caudal fins is seldom of any value in the classifi- 

 cation of fishes. 



The abbreviations, D., dorsal fia; A., anal; C, caudal; P., pectoral; V , ventral; 

 B., branch! jstegals, and lat. 1., lateral line, aire frequently used, especially in enumerat- 

 ing the number of fin ra^s or scales. 



Artifical Kby to the Orders of Pisces Reprksbntbd in Ohio. 



*Tail evidently heterocercal ; ventral fins abdominal; no true spines, bnt some of the 

 fins usually provided with fulcra, {Ganoidei). 



a. Skeleton cartilaginous ; body naked or with series of bony bucklers. 

 66. Mouth narrow, inferior, toothless, preceded by four barbels. 



Chondrostki, 3. 

 hi. Mouth terminal, broh,d, with minute deciduous teeth ; snout prolonged into a 



spatulate process. Selachostomi. 2. 



aa. Skeleton bony ; body scaly. 

 CO. Sodloa ganoid, i. e. rhombic enamelled plates ; dorsal fin short ; no gular 



plates. GlKGLYMODI. 4. 



CO. Scales cycloid ; dorsal fin very long ; a broad gular plate. 



Halkcomoephi. 5. 

 **Tail not evidently heterocercal, {Teleostei). 

 d. Maxillaries wanting, or confluent with. the palatines; body serpentiform ; no 

 ventral fins ; vertical fins confluent, or nearly so around the tail. 



Enchelycbphali. 6. 

 dd. Maxillaries present, rudimentary, each forming the base of a long barbel ; no 

 scales ; dorsal and pectoral fins each with a single strong spiue. 



Nematognathi 7. 

 ddd. Maxillaries, complete, not forming the base of a long barbel. 

 e. Ventral fins (in our species) composed each of a strong spine and a radimen- 

 tary ray ; dorsal with free spines; body soaleless, naked or mailed. 



Hkmibranchii. 9. 

 ee. Ventral fins if present, not as above. . . . Tjclkocephali. 8. 



