62 MR. c. TATE REGAN ON [May 12, 



about 2i times in that of head. Sc. 43-46 ^g^y^, extending on 

 head to posterior margin of eye, 4 rows between soft dorsal 

 and lateral line. 5-7 dark vertical bars on upper part of body, 

 extending on to dorsal fin ; a light area on lower part of body in 

 front of anal ; a pair of conspicuous black spots on base of caudal. 

 Diagnosis based on four examples (including the types of 

 C. disjnlurus) from the W. Indies, the largest 98 mm. in total 

 length. The smaller size of the specimens described makes it still 

 more notable that the eye is smaller and the mouth extends farther 

 back than in &'. auriga, whilst other differences are sufficiently 

 numerous. 



PRISTIPOMATIDiE. 



Diagramma cavifrons Cuv. &, Val., from the coast of Brazil, 

 has been redescribed by Boulenger as D. goeldii ; this was 

 doubtless due to Giinther having ei-roneously placed this species 

 in Pristipovia, so that it appears from the Biitish Musevim 

 Catalogue that the genus Biagrainfima is exclusively Indo- Pacific. 

 The synonymy of this species is as follows : — 



Diagramina cavifrons Cuvier & Valenciennes, v. p. 290, pi. 123 

 (1830). 



Pristipoma cavifrons Giinther, Cat. i. p. 286 (1859). 



Genyatreviihs cavifrons Gill, Proc. Ac. Nat. Sci. Philad. 1862, 

 p. 256. 



Genyatremxis htteics * Jordan & Fesler, Proc. Ac. Nat. Sci. 

 Philad. 1889, p. 504 ; Jordan & Evermann, Fishes IST. Am. ii. 

 p. 1342(1898). 



Diagramma goeldii Boulenger, Ann, Mag. ISTat. Hist. (6) xx. 

 1897, p. 294. 



Mylacrodon, gen. nov. 



Body compressed. Scales moderate, cycloid ; lateral line 

 complete, concurrent with the dorsal pi'ofile, the tube straight, not 

 extending the whole length of the scale. Mouth moderate, 

 protractile ; the maxillary slipping for most of its length under 

 the prasorbital, exposed distally, without supplemental bone. A 

 series of conical teeth in each jaw, posteiioi'ly becoming shorter, 

 rounded and molar- like ; internal to these anteriorly one or two 

 series of small rounded molars ; no teeth on tongue or palate. 

 Head scaly ; nostrils close together, rounded, the anterior largest ; 

 no pit below the chin ; prpeoperculum serrated ; operculum not 

 spinate. Gill-membranes united far forward, free from the 

 isthmus ; seven branchiostegals ; pseudobranchiaj present ; gill- 

 rakers rather short. Two dorsals continuous at the base, with 

 XI, I 13 rays; anal with III 10 rays; both with a scaly 

 sheath at the base. Pectorals asymmetrical, with 18 rays, 

 the upper rays longest ; ventrals below pectorals, each with 

 a strong spine and a scaly axillary process ; caudal emarginate. 



* The iclontity of this species with Lvtianus liitens Bloch is extremclv doubtful. 



