6 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iie 



well as geographically between the western Atlantic and the eastern 

 Pacific species. 



I do not consider Grammonus leucos Osorio, 1917, to be referable 

 to Oligopus, as the original description mentions the presence of teeth 

 on the palatines. Professor Fernando Frade has informed me that 

 the type cannot be found in the Museu Bocage. 



Key to Species of Oligopus 



la. One or no pores in lateral head canal system; 1 or 2 pores in supraorbital 

 canal. Spines along preopercle margin absent or small and weak. 

 2a. Dorsal fin rays 68-87; anal fin rays 51-62; vertebrae 40-46. 



3a. Dorsal fin rays 68-74; anal fin rays 51-52; vertebrae 40-42 . . . O. ater 

 3b. Dorsal fin rays 83-87; anal fin rays 57-62; vertebrae 44-46. 



4a. Lateral scale rows about 120. Upper row of lateral line organs 

 about 35-45; lower about 35-40; dip in ventral lateral line in vent 



area O. longhursti 



4b. Lateral scale rows about 75-85. Upper row of lateral line organs 

 about 21; lower row about 25-30; no dip in ventral lateral line. 



O. robustus 

 2b. Dorsal fin rays 93-115; anal fin rays 71-91; vertebrae 48-53. 



5a. Lateral scale rows about 80; anal fin rays 71; 6 pores in infraorbital 



canal system O. waikiki 



5b. Lateral scale rows 97-115; anal fin rays 76-91; 5 or fewer pores in infra- 

 orbital canal system O. diagrammus 



lb. Three or 4 pores in lateral head canal system; 2, 3, or 4 pores in supraorbital 

 canal. Several small but distinct spines along preopercle margin. 



O. claudei 



Oligopus ater Risso 



Plate 2 



Oligopus ater Risso, 1810, p. 142, pi, 11, fig. 41 (original description. Gulf of Saint 

 Hospice, France). — Fowler, 1936, p. 1329 (description, synonymy). 



Oligopiis niger Risso, 1826, p. 338 (new name for 0. ater Risso, 1810; description). 



Pteridium ater Swainson, 1839, p. 302 (0. ater Risso listed under Pteridium Scopoli). 



Gadopsis ater Filippi, 1856, p. 170 (description of swim bladder, new genus pro- 

 posed) . 



Pteridium alrimi Filippi and Verany, 1859, p. 195, fig. 6 (synonymy, description, 

 swim bladder, relationships). — Doderlein, 1886, p. 73 (comparison with 

 Pteridium armatxim). — Giinther, 1887, p. 105 (description, 1 specimen from 

 Mediterranean). — Bellotti, 1888, p. 222 (sexual dimorphism in dentition of 

 specimens from Nice and nearby, comparison with Pteridium armatum.) — 

 Lo Bianco, 1909, p. 741 (pelagic postlarvae circa 30 mm., January, February, 

 March, in Gulf of Naples). — D'Ancona, 1938, p. 159, figs. 2, 4, 8 (comparison 

 with P. armatum, description, based on material from Nice, Naples, and 

 Zirona, nomenclature, relationships, distribution, additional references not 

 here cited). 



Grammonus ater Goode and Bean, 1896, p. 317 (new genus proposed, synonymy, 

 compiled description). — Tortonese, 1958, p. 333 (listed, doubts that G. ater 

 (Risso) and G. armatus (Doderlein) belong in different genera). 



Verater ater Jordan, 1919a, p. 343 (new genus proposed). 



