APPENDIX F. FISHES. 217 



longest. They all (the soft rays) bifurcate from their middle, and then 

 again subdivide from four fifths of their length to the tip. The caudal 

 fin.is subcrescentic posteriorly; its angles are rounded; its length con- 

 tained five times and a half in that of the body and head together. The 

 central rays bifurcate three times upon their length. There are seventeen 

 rays in all, with a few rudimentary ones. The anal is well developed ; 

 its three anterior spiny rays are the shortest, and not very conspicuous. 

 The eight remaining ones are soft and articulated ; similar in structure 

 to those of the dorsal fin. The ventrals are inserted behind the base of 

 the pectorals ; their tip, when bent backwards, reaching the anus, which 

 is situated a quarter of an inch in advance of the anterior margin of the 

 anal fin. This is subtriangular, posteriorly subtruncated, composed of an 

 anterior spiny ray, and five soft and articulated ones, which bifurcate 

 twice. The pectoral extends backwards as far as the ventrals. Its rays, 

 fifteen in number, are all soft and very slender, bifurcating twice. Only 

 thirteen of these rays are well developed. The formula of the fins is as 

 follows : 



D X. 9 + 1 ; A III. 8 ; C 2. 1. 8. 1. 1. 1 ; V I. 5 ; P 15. 



The scales are of medium size, longer than high, truncated anteriorly, 

 rounded posteriorly, and finely denticulated, as seen in fig. 4. The lateral 

 line does not extend beyond the insertion of the rays of the caudal, the 

 base of which is covered with scales irregularly disposed. The smallest 

 scales are observed under the head, upon the throat ; the largest on the 

 peduncle of the tail. 



The color is not sufficiently preserved in the single specimen collected 

 to admit of description. Traces of irregular lines are, however, visible 

 upon the cheeks and opercular apparatus. 



Found in Otter creek, Arkansas. 



Plate XII, fig. 1. Pomotis longulus, in profile, and of the size of life. 



Fig. 2. A dorsal scale taken on the middle of the back, above the 

 lateral line. 



Fig. .3. A scale from the lateral line, exhibiting the mucous tube. 



Fig. 4. A scale from the sides of the abdomen, below the lateral line. 



Figs. 2-4 are magnified twelve times. 



2. POMOTIS BREVICEPS, B. & Gr. 

 Zoology, PI. XIII. 



Spec. char. — General form short and stout, subelliptical ; opercular 

 flap very much developed, and directed upwards, black with a lighter 

 margin. Twenty-four rows of scales across the line of greatest depth, 



