ICHTHYOLOGY. 



19 



Family POLYNEMIME. 

 POLYNEMUS OCTONEMUS, Grd. 



Plate X, Figs. 5—9. 



Spec. Char. 



The head enters about four times and a half in the total length, the snout being sub-conical, the mouth rather 



large and wide, the posterior extremity of the maxillary extending to a vertical line drawn considerably behind the orbit. The 



eye is large and sub-circular; its horizontal diameter being contained about four times in the length of the side of the head. The 



edge of the preopercle is finely serrated, the lower spine, situated near the convexity of the limb of that bone, is much larger 



than the rest. The thoracic filaments are eight in number, the tip of the longest ones extending beyond the origin of the anal 



fin. The posterior extremity of the ventrals barely reach the vent and extend somewhat further backwards than tho extremity 

 of the pectorals. 



The scales are deeper than long, pectinated upon their posterior section and furrowed upon 

 the anterior section. The lateral line, from the scapular region, takes a direct course towards 

 the middle of the caudal fin. The accompanying figure will give an accurate idea of the form 

 and relative position of the fins : 



Br. VII: VII; D Till, I, 12 ; A III, 13 ; C 6, 1, 8, 7,1,5; VI, 5; P 15. 



Plate X, fig. 5, represents Polynemns octonernus size of life ; fig. 6 is a magnified view of the 

 head in order to show more particularly the denticulations of the limb of the preopercle ; fig. 7 

 is a dorsal scale ; fig. 8, a scale from the lateral line ; and fig. 9, a scale from the abdominal 

 region. 



List of specimens. 



Catal.No.of 



No. 



spec 



Age. 



Locality 



When col- 

 lected. 



Whence obtained 



Orig'l 



No. 



Nature of 

 specimens 



Collected by 



739 

 IG'2 



8 

 2 



Adult. 



Brazos Santiago, Texas.. 



Young Galveston, Texas 



1853 

 1853 



G. Wiirdemann 



Lt. A. W. Whipple 



3 



Alcoholic. 



• • • •CIO • ■ • • 



G. Wiirdemann 



Dr.C.B.Kennerly 



Family ATHEKINIME. 



Two species of this family may be recognized in the collections under examination, one from 

 the fresh waters of the interior of Mexico, specimens of which were collected by Major Rich and 

 Jno. Potts, esq., the other from the salt and brackish waters of lndianola, St. Joseph's island, 

 Brazos, and the mouth of the Rio Grande del Norte (Rio Bravo), the specimens having been 

 collected by Jno. H. Clark, under Col. J. D. Graham and Major Emory, and by Mr. Gustavus 

 Wiirdemann, of the United States coast survey. Both of the above species belong to the genus 

 Atherinopsis , and will be described on a future occasion. 



Family MUGILIDAE. 



The body is sub-cylindrical, owing to the thickness of the dorsal region. The scales generally 

 are large, ctenoid in structure, and cover likewise the upper surface of the head. There is no 

 lateral line properly so to be called, every scale being provided with a mmous hole. The dorsal 

 fins are widely apart ; the ventrals, almost abdominal, are situated on a vertical line drawn 

 between the pectorals and the anterior dorsal. The teeth are exigu >us, and sometimes even 

 wanting. The maxillar bones are small and almost buried in the thickened lip which covers 

 the premaxillaiies. The sub-orbitar bone is often contiguous to that lip, when the mouth is 

 closed, concealing entirely under its edge the maxillary. 



