338 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY - IV. 



159. ZYGOXECTES Agassiz. 



Top Minnows. 



(Micristius Gill.) 

 (Agassiz, Am. Jonrn. Sci. Arts, IS")!, l:>r>: type Pcecilia oUoacca Storer.) 



This genus is closely related to Fiindnlits, differing chielly in the small 

 size and posterior position of the dorsal, \vhich has usually less than 

 ten rays and is commonly inserted behind the front of the anal tin. 

 The species are smaller in size than those of Fnndulus, and different in 

 appearance, so that we feel reluctant to unite the two genera, although 

 the technical differences are very slight. From the Old World genus 

 Haplocliihis, Zygonectcs is distinguished by the short anal fin. The fe- 

 males of Zygoncctes are scarcely distinguishable from those of Gambusia. 

 Species all American. Surface swimmers, feeding upon insects. 



(fyj-w, yoke ; vr/Kryr, swimmer ; they being said to swim in pairs.) 



* Body rather elongate. (Zygonectcs.) 

 a. Sides without black band. 



25. rubrifrocis Jordan. 



Body moderately stout, little compressed, not elevated, the caudal 

 peduncle deep; head rather long, broad between the eyes, fiat above; 

 eyes large, 3 in head, their range horizontal; mouth rather larur. 

 Teeth small, nearly even, in a narrow baud. Scales moderate. Dorsal 

 in i very short and small, placed a little behind the anal or about even 

 with it, its position in the males rather more posterior; anal short, high 

 in the males; ventrals very small; pectorals small. Color, males dark 

 olivaceous, with a dark, bronze-orange spot on each scale posteriorly, 

 much as in Fttmlulus catcnatus. Below, these spots are bright orange. 

 Faint, narrow vertical, orange bars along the lower and posterior part 

 of the body. Vertical fins with orange spots. Jaws and space in front 

 of eyes bright orange-red; paired lins dusky. Females alnio>t uniform 

 !ir.iss\ --olivaceous, without evident spots or red markings. Head :\\ in 

 Irngth to base of caudal ; depth ;J : . D. 7 or 8; A. 8 or 9; Lat. 1. 3L>; 

 L. transv. 11 orli'; B. 5. L. 1U-3 inches. San Sebastian River, Flor- 

 ida, a larger species than most in the genus, and with the dorsal (in less 

 posterior. 



Mcinl.-Mi. Proc. r. >. Nat. Mus. i-7:>, -J:t7.) 



587. Z. Eirttshnlli .Ionian. 



Body rather stout, deep and 'compressed, the profile nearly straight, 

 the back little elevated, and the caudal peduncle deep; head moderate; 



