Fishes of the JVestern North Atlantic 433 



Synonyms and References: 



Odontognathus mucronatus Laccpide, Hist. Nat. Poiss., 2, 1800: 221, pi. 7, fig. 2 (orig. descr. under "L'odon- 

 tognathe aiguillone," but a footnote gives the binomial Odontognathus mucronatui\ type local., Cayenne, 

 French Guiana); Jordan and Evermann, Bull. U. S. nat. Mus., 47(1), i8g6: 438 (descr., synon.); 

 Eigenmann, Mem. Carneg. Mus., 5, 191 2: 447 (synon., diagn., Georgetown, British Guiana); Norman, 

 Ann. Mag. nat. Hist., (g) //, 1923 '• 15 (synon., descr.); Jordan, Evermann, and Clark, Rep. U. S. 

 Comm. Fish. (1928), 2, 1930: 45 (ref. to orig. descr.). 



Gnathobolus mucronatus Cuvicr and Valenciennes, Hist. Nat. Poiss., 21, 1848: 91 (descr.). 



Pristigaster mucronatus Giinther, Cat. Fish. Brit. Mus., 7, 1868: 462 (synon., descr.). 



Odontognathus compressus Meek and Hildebrand 1923 

 Figures 1 10, 1 1 1 



Study Material. Numerous specimens, about 30-145 mm TL (caudal damaged 

 on 30-mm fish), 23—123 mm SL, including the holotype and 25 paratypes, from the 

 Atlantic coast of Panama, and a few lots from the Gulf of Venezuela. 



Distinctive Characters. The nearest relative of O. compressus is O. panamensis of the 

 Pacific coast of Panama, but these species diifer in having 52-60 and 65-68 anal rays, 

 respectively. Furthermore, in compressus the dorsal fin is notably in advance of the 

 middle of the anal base, whereas in panamensis it is about over the middle of the anal 

 fin. Its relationship with O. mucronatus is shown in the Key to Species (p. 430). 



Description. Proportional dimensions in per cent of standard length, and counts, 

 based on Study Material., specimens 23-123 mm SL. 



Body: depth 23.5-28.5. Pectoral fin: length 21-25. 



Caudal peduncle: depth 7.25-8.3. Distance from snout to origin of: dorsal 



Head: length 18-21; depth 18-22. 65-67. 



Snout: length 4.2—5.1. 



Eye: diameter 5.25-6.25. Scales: lost, ca. 36-43 pockets. 



Interorbital: width 2.0-2.75. Ventral scutes: 25-29. 



Maxillary: length 12-16. Vertebrae: 46 or 47 (3 specimens). 



Mandible: length 9.3-10.2. Fin rays: dorsal 11-14, usually 11 or 



Anal fin: length of base 47-54. 12; anal 52-60; pectoral 12-14. 



Body elongate, excessively compressed, its greatest thickness about o. 1 7 of its 

 depth, its greatest depth 3.5-4.25 in SL; the dorsal outline of head concave in adults; 

 the ventral outline strongly convex anteriorly. Caudal peduncle much shorter than 

 depth, its depth 2.3-2.9 in head. 



Scales mostly lost; very thin, deeper than long, with nearly smooth margin, 

 without evident vertical striations. Ventral scutes well developed, the last 8—10 with 

 serrate margin. 



Head small, its length 4.75-5.5 in SL, its depth at vertical from slight cross- 

 groove at occiput 4.5-5.55. Snout a little shorter than eye, 3.6—4.7 in head. Eye 2.9- 



