398 EXPLORATIONS ACEOSS THE GEEAT BASIN OF UTAU. 



MOEONE INTEERUPTA, Gill. 



Synonymy. 



Lai'.hax ciiKvsoi'8 GiranJ, Gciioial Roport niioii the ZoJUosy of tlic several Pacifie Kailroatl routes, Icbtliyology, p. 29 



(pi. xi, ligs. 1-4). 

 Laukax ciirysops Girard (fii^urcd iu Govonior Stephen's Report). 

 MOHONE iXTEliRl'i'TA Gill, Proceediugs Acad, of Nat. .Scicnees of Pbila., IHGO, p. 118. 



The body is oblong ovate, with the Ijack at tlie commeiirement of the doi\sal iin 

 shghtly gibbous. The greatest height under the spinous dorsal equals three-tenths of 

 the length from the snout to the concave margin of the caudal fin. The dorsal outline 

 slightly declines under the spinous dorsal and little more under the rayed. The abdom- 

 inal outline to the anal fin is convex, and thence ascends quite rapidly iu a concave 

 curve to the base of the caudal liii. The i)eduncle l)ehind the anal fin exceeds a seventh 

 of the extreme length, and at the base is equal to al)out a ninth. 



The head is conical in profile, slightly depressed at tlie nape, and thence nearly 

 straight to the snout. The head from the snout to the opercular spine forms three-tenths 

 of the length, its length being scarcely less than the height of the body. The eyes are 

 moderate, the diameter being between a foui-th and a fifth of the head's lengtli. Tliey 

 are distant much more than a diameter from the snout. 



The anterior margin of the preoperculum acUances oblitjuely downward and for- 

 ward ; the pectinate margin is nearly vertical; the <listance l)etween tlie margins near 

 the angle exceeds half the diameter of the eye. The teeth of the postei'ior margin 

 become stronger toward the angle ; the inferior margin is weakly serrated along its 

 posterior half. The operculum has two spines, separated liy an ol)li(pie sinus; tlie 

 superior one is blunt and almost rounded. 



The dorsal fin commences at a vertical intermediate l)etweeii the bases of the j)ec- 

 toral and \entral fins find is of a triangular form, the fourtli ray lieing the largest and 

 e(pialinu' the length of the pectoral fin; the spines have the same form and arrangement 

 as those of ]\£oroii<- uiiici-haiKi. The second dorsal is connected Ijy a membrane as in 

 Moroiie amcrimna ; its spinous or first ray is little more than half the length of the first 

 articulated one, which itself is nearly as long as the fourtli dorsal spine; the fin thence 

 decreases iu height toward its last i-a\, which is shorter than the spinous ray. 



The anal fin connnenccs under tlie fimrtli or iifth articiilate<l ray of the second 

 dorsal, and alioiit four of its ra)'s are jiosterior to the termination of that fin; the first 

 s])ine is short and robust; the second almost two and a half times longer, compressed, 

 iind very strong; the third is alino,st as long as the second, but much more slender. 

 The first articulated ray of the anal is longer than the spines, and about twice as long- 

 as the last; the outlim- of the tin is slightly emarginated. 



The iirst rav of the pectoral fin is, as usual, articulated, but simple; the third is 

 longest and branched, and equals the liase of the second dorsal. 



The veiitrals are about as long as the pectorals; the lengtli of the spine is eqiuil 

 to two-thirds of that of the first or second branched rays. 



The radial fiiniuila is as follows: 



1). IX. I. 12; A. III. 10; G. 4. L S. 7. I. 3; P. 2. 14; V. 1. 5. 



The scales are of about the same size as in the Moroiie americana, the lateral line 



