lY. — A Review of the American Species of Thread-fins 



(Polyneviidse). 



BY PHILIP H. KIRSCH. 

 Read October 14, 18S9. 



In this paper I have given the synonymy of the Thread-iins or 

 Polynemidee known to inhabit American waters, and an analytic 

 ke}'^ by which the species may be distinguished. All the specimens 

 examined bv me belong to the Museum of the Universitv of Indiana. 

 Most of them were collected by Dr. Jordan and his assistants. 



Indiana Univeesity, July 8, 1889. 



Characters of the Polynemid^. 



Body oblong, compressed and covered with rather large, looseh^ 

 inserted, ctenoid scales. Lateral line continuous, continued on the 

 tail, usually forked with a branch on each lobe. Head entirely 

 scaly ; snout more or less conical, projecting over the mouth, which 

 is rather large, inferior, with lateral cleft ; premaxillary protractile, 

 its spine vertical ; maxillary without supplemental bone, extending 

 much beyond the eye, which is anterior, lateral, rather large, with 

 adipose eyelid. Tilliform teeth on jaws, palatines, and sometimes 

 on vomer. Pseudobranchiae concealed. Branchiostegals T. Gill- 

 membranes separate and free from the isthmus. Gills 4, a slit be- 

 hind the fourth. Two separate dorsals, somewhat remote from each 

 other, the first of 8 feeble but rather high spines, the first and last 

 spines very short, the third longest ; the second dorsal equal to first 

 in height but base somewhat longer, of soft rays only. Anal fin 

 either similar or much longer than soft dorsal ; caudal fin rather 

 long, widely forked. Second dorsal, anal, and caudal fins more or 

 less covered with small scales ; the first three or four dorsal spines 

 winged. Yentrals I, 5, abdominal, but not far removed from pec- 

 torals ; pectoral fins moderate, placed low, in two parts, the lower 

 . Annals N. Y. Acad, Sci., V, April, 1890.— 16 



