of Glupeid Fishes. 21 



7. Pliosteostoma, gen. nov. 



Differs from Neosteus in the absence of the pelvic fins. 

 Origin of dorsal behind that of the anal. Scales withont 

 transverse grooves. 



A single species from America. 



Pliosteostoma lutipinnis. 



Pristiqaster lutipinnis, Jord. & Gilb. Proc. U.S. Nat. Miis. iv. 18S1, 



p. 340. 

 Opisthoptcrus Intipiimis, Jord. & Everm. Bull. U.S. Nat. Mas. xlvii. 



1896, p. 437. 



Depth of body 4 to 4^ in the length, length of head 4 to 

 4J. Yentral profile not much more convex than dorsal. 

 Snout shorter than diameter of eye, vrhich is 2^ to 3A in 

 length of head ; maxillary obtusely pointed posteriorly, 

 extending to below middle of eye ; posterior supramaxillary 

 reaching to end of maxillary ; lower jaw projecting. Ridges 

 on head diverge posteriorly. 18 gill-rakers on lower part of 

 anterior arch. Scales about 45/11 ; ventral scutes 27-28. 

 Dorsal 13 ; origin about equidistant from base of caudal and 

 occiput. Anal 53 ; origin nearer base of caudal than end of 

 snout ; length of base 2| to 2|in length of body. Pectorals 

 a little shorter than head. ? 



Pacific Coast of Mexico. 



Seven specimens, 70-180 ram. in total length, from 

 Mazatlan. 



8. Chirocentrodon, GUnth., 1868. 



The relationships of this genus are uncertain. It agrees 

 with the preceding genera in having a long anal fin, but 

 may easily be distinguished from all of them by the struc- 

 ture of tlie mouth. Body oblong, compressed ; abdominal 

 serrature commencing on the thorax. Maxillary adherent 

 to prsemaxillary, their dentigerous margins continuous ; two 

 supramaxillaries. Teeth on prsemaxillary uniserial, with 

 2 or 3 anterior canines ; maxillary teeth uniserial, unequal; 

 teeth in lower jaw uniserial, with a pair of canines inside ; 

 narrow bands of teeth on vomer, palatines, and pterygoids ; 

 a patch oE teeth on tongue. Anal with more than 30 rays ; 

 origin just in front of that of dorsal. Pelvics very small. 



A single species from the AVest Indies. 



Chirocentrodon taniatus. 



Chirocmtrodon tcpniatus, Giinth. Cat. Fish. yii. p. 463 (1868) ; Jovd. & 

 Everm. Ball. U.S. Nat. Miis. xlvii. 1896, p. 435. 



Depth of body 4| to 5 in the length, length of head 4i to 



