280 PROCEEDINGS OP THE ACADEMY OF 



little more anteriorly situated in the Delaware specimens, and there is a row 

 of scales more below the lateral line than in Susquehanna specimens. With 

 typical specimens only, these might be regarded as representing two species, 

 and as such I have already alluded to them ; * but in the large number of in- 

 dividuals at my disposal, I find transitions in all the points. The Delaware 

 specimens more nearly resemble the H. cornutus, figured by Dr. Storer. 



Squalius proriger. 



Until more characteristic points are presented, I provisionally preserve un- 

 broken a series of beardless Chilognath Cyprinoids, with pharyngeal teeth 

 2 or 14 or 5 : 5 or 4 1 or 2, of the type uncinato-subconici raptatorii, and 

 not crenate ; the scales, with the usual extent of surface exposed ; the 

 isthmus not wide, and tbe anal fin short. The long anal fin dis'inguishes 

 Albnrnus from it ; and the narrow exposed scale surface and masticatory 

 teeth, Hypsilepis. Clinostomus Gir., may be said to be distinguishable by the 

 prominent mandible and large gape, but Sq. lepidus (Heck. Fische Sy- 

 riens, 89, ) is quite similar in the former point, and the Clin, photogenisf 

 has the cleft as short as in most Squalii. Ptychochilus Ag. seems not yet 

 to have been sufficiently distinguished from Clinostomus, and resembles 

 Squalius even more in its terminal mouth. If different genera are here united 

 erroneously, it is because their characters have as yet not been pointed out. 

 They embrace five Pacific slope species, six Eastern American, and many 

 from the old world. 



In the species now named the prolongation of the lower jaw is very great : 

 it presents a symphysial knob beyond and above the premaxillary border. 

 End of the maxillary opposite the middle of the pupil. Angle of opercular 

 outline less than 90. Head narrowed anteriorly ; eye four times in its 

 length : latter four times in length to concavity of tail. Greatest height 5| 

 times in the same. Ventrals a little in advance of dorsal : from front base of 

 latter to base of tail equal from former point to half way between end of muz- 

 zle and nares. Teeth 2-5 4*1 in two specimens. Scales small, with especi- 

 ally strong concentric lines, -Lft62. Dorsal high 1-8 ; Caudal deeply furcate, 19 ; 

 Anal rather elongate, 1*81. V. 8, not reaching vent ; P. 14, elongate. Total 

 length three inches. 



Rufus brown above half way to the lateral line ; a dark shade from end of 

 muzzle to tail, covered with silvery, the latter extending to the belly. Sides 

 punctulate anteriorly. 



* Proc. Acad. Nat. Sci., Phila. 1861, 522. 



t Squalius photogenis. A species resembling some Alburni in its large caducous scales and 

 attenuated lotm. Mouth quite oblique ; under jaw scarcely projecting: maxillary not reaching 

 line of margin of orbit. Head entering 4 times into length to fork of caudal ; greatest depth 

 seven times. Back broad. Fins D. narrow 8; C. 19, A. 1 10. V. little anterior to dorsal 9. P. 

 narrow fulcate 13. Scales ^39. Radii stronger than concentric lines. Prom base of caudal to base 



of first dorsal ray, equal from latter to anterior border of iris. 



Above pale ochre, with a median brown line, and one on each side, from opercular upper angle 

 to ta.l. fc ides and below bright silvery, especially brilliant on the operculum and suborbital re- 

 gion. Lips blackish edged. 



Length three inches. 



Two specimens from the Youghiosrheny River, Pa. This maybe the species on which Rafinesque 

 established his Luxilas interruptus, but the discrepancies are so numerous that the identifica- 

 tion cannot be made 



Besid' s the S. {Clin.) funduloides of Girard, another species occurs in the waters flowing 

 into the .Susquehanna. This, which may be called S. hyalope, was obtained in the Conestoga 

 by J. Sta after. Its form is that of a true Squalius as S. ce p hal u s, not having tbe prominent 

 mandible and compressed b"dy of the species included by Girard in Clinostomus. Mouth little 

 oblique, extending to beyond opposite anterior border of orbit . Muzzle obtuse; head elongate, 

 broad, entering length to base < f caudal 3| times. Dia-r.eter of eye contained Si times in length 

 of head, equal lower posterior border of operculum. Base of caudal to front base of dorsal equal 

 from latter point to anterior border of pupil of eye. Teeth 1.4 5.1. Greatest depth 4j times in 

 length to base of caudal. Scales -?45, with ten or eleven strong radii visible, pins small; radii 

 ]). 8. C. 17. A. 1-8, V. 8. P. 11. Total length about three inches. Color whitish, becoming 

 bluish dorsally ; nc markings. 



[Dec. 



