812 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



The radial formula iu thk fish is : D. Ill— 11; C. 6— 19— G; A. Ill— 7. 

 V. 7. The vertebrae are: D. 13; C. 17. Centra between the lines of 

 the first interneural and first interhsemal spines, 10. Ten rows of smttll 

 scales visible above the vertebral column. 



The general form of the fish is stout, and the caudal peduncle is deep, 

 The-top of the head is convex, and the eye large. The front descends 

 abruptly to the rather projecting muzzle in the specimen, but whether 

 this is a distortion or not is uncertain. The coracoid is wide and well 

 produced backward, while the clavicle is, as usual, directed forward. 

 The femur* is slender, and connected with its fellow by a posterior 

 transverse bar. The greatest depth is a little less than one-fourth the 

 length without the caudal fin. The diameter of the eye is one-fourth 

 the length of the head. The origin of the ventral fin is in advance of 

 the first dorsal ray ; the origin of the anal is below the penultimate 

 dorsal ray. The caudal fin is openly forked. 



j\Ieas7(rements. 



II. 



Total leugth O.OGl 



Length of head 0.016 



Length to Hue of ventral fin .• 0.020 



Length to line of dorsal fin 0.022 



Length to line of anal fin 0.031 



Length to base of caudal tin 0.04S 



Depth at caudal peduncle 0.008 



Depth at dorsal si>iue 0.011 



The more numerous rays of the dorsal fin and more numerous scales 

 are among the characters which distinguish this species from the two 

 heretofore known. It is dedicated to Dr. Frederick M. Endlich, geolo- 

 gist in charge of one of the parties of the United States Geological Sur- 

 vey of the Territories under Dr. F. Y. Hayden. 



Amphiplaga beachyptera. Cope, gen. et sj). nov. 



Char. gen. — Generally as in Erismatopterus, but with strongly ctenoid 

 scales. The dorsal fin Is over the abdomen, and is supported by a few 

 strong, adherent spines in front, which rest on stout interneurals ; the 

 soft rays have no interneurals, either in this fin or the anal. They are 

 present in Erismatopterus. The ventrals originate a little in advance of 

 the line of the dorsal, and the caudal fin is deeply forked. This genus 

 approximates Aplirodedirus. 



Char, specif. — Eadii : D. II — 8; A. II I — 4. Yertebrie of the caudal series 

 15. Scales : transverse row, 22 ; longitudinal row behind first interneural 

 bone, 40. The only specimen I possess lacks the head, so that various 

 characters cannot be ascertained. The depth of the body at the first 

 dorsal si)ine enters the length from that point to the base of the caudal 

 fin two and a half times, giving a general form of medium proportions. 



*Before the homologies of these bones were studied, authors frequently called them 

 imlies. 



