SYNOPSIS OF THE CYPRINIM1 OF PENNSYLVANIA. 



387 



Height of dorsal ono and one-half its base, first ray (osseous) half the height, nearer end muzzle than origin 

 caudal ; base of anal more than two-thirds height of first rays. 



Total length 2.875; caudal fin .5; middle origin caudal to first anal ray .78; end muzzle to origin dorsal 

 fin 1.187. 



In this specimen the differences between II. huclsonius and the II. procne, which I had 

 once suspected to be the young, arc marked. First, the invariably greater number of 

 scales above and below the lateral line ; second, the constantly normal number of anal 

 rays ; the deeper caudal peduncle, which is one-third its length from first anal ray ; the 

 broader lateral band, which is in the procne but 1.5 rows scales in width. Pharyngeal* 

 teeth I could only find 1.4 — 4.0. There may still be some question as to the pertinence 

 of tins specimen to II. hudsonius. 



ALBUKNELLUS, Gimrd. 



Proceedings Acad. Nat. Sci. Phila., 1856, 193. 



This genus represents and nearly resembles the Alburnus of the Old World ; whether 

 the latter genus occurs on the North American Continent or not is as yet unknown. 



The dentition is represented by the formula 2.4 — 4.2; the teeth are without mastica- 

 tory surface proper, except perhaps in A. rubrifrons. There is a narrow, scarcely worn 

 plane in both A. jaculus and A. arge, on one or two of the teeth. 



In the three species here compared the extremity of the maxillary bone reaches the 

 vertical line of anterior margin of the orbit, and the distance from the base of first dorsal 

 ray to caudal equals from former to posterior margin or middle of orbit. 



Diameter of eye less than to muzzle, four times in length of head; head five times in total. Scales 6 — 39 — 3. 

 A dark vertebral line, a dark lateral band, sides and belly silver. kubrifuons. 



Diameter of orbit less than to muzzle, 3.5 to 3.7 in length of head ; latter five times in total, four and one- 

 fourth to base of caudal. Scales 6 — 39 — 2, lateral line most decurved. No dorsal or lateral band, sides and belly 

 silvery. jaculus.* 



* Alburnellus jaculus, m. 



A very elongate, light olivaceous species, which occurs in shoals in the clear water of the St. Josephs River, 

 and its tributary the Dawagiao. These streams debouch into the head of Lake Michigan from the east. 



Muzzle from orbit longer than diameter of latter ; end of maxillare opposite anterior margin orbit, mandible 

 acuminate without symphyseal knob. Frontal breadth two-thirds temporal, equal orbit's diameter. Greatest 

 depth seven and a half times in length (including caudal), equal from end muzzle to preopcrcular border. First 

 dorsal ray equidistant between origin of caudal and posterior rim or middle of orbit, as far behind opposite ven- 

 trals as the posterior ray is in advance of anals. Base of dorsal equal two-thirds its height; base of anal equal 



