Jordan and Evermann. — Fishes of North America. lUi'J 



I/. Ventral fins well separated, the interspace about equal to wiiltli of 

 their base. 

 A. Middle line of belly with more or less enlarged, caducous plates, 

 which are shed at certain seasons, leaving a naked strip. 



IIadropteuus, 466. 

 Wi. Middle line of belly with small, persistent scales like those of 

 sides. Hypoiiomis, 467. 



jr. Premaxillaries protractile, a groove separating them from the skin of the 

 I'nrehead, rarely crossed by a narrow freuum in one species (shmnardi) . 

 i. Anal spines 2, both well developed, the first usually the longer, the 

 second rarely obsolete. 

 .;. Maxillary normal, free from the preorbital, except at base; vomer 

 usually with teeth. 

 A-. Anal fin rather large, scarcely smaller thau second dorsal; 

 mouth not very small; belly naked or with caducous 

 plates, at least anteriorly; gill membranes scarcely con- 

 nected, ventral fins well separated. Cottogastek, 4C8. 

 kk: Anal fin short and small, much smaller than second dorsal; 

 mouth small; belly covered with ordinary scales; gill 

 membranes broadly connected across the isthmus; ven- 

 tral fins inserted close together. Ulocentr.4, 469. 

 Si. Maxillary adnate to the preorbital for most of its length, and 

 therefore nearly immovable; mouth very small, inferior; no 

 teeth on vomer; ventral fins close together. Diplesion, 470. 

 a. Anal spine single, obscure; dorsal spines usually 9, slender; anal fin 

 small, much shorter than soft dorsal; ventral fins well separated. 



BOLEOSOMA, 471. 



ee. Body extremely elongate, hyaline, subterete, the belly mostly naked; 



lateral line complete; head long, pointed; gill membranes somewhat 



united. 



/. Premaxillaries not protractile, free only at the sides; dorsal spines 14; 



anal fin large, with 1 spine; scales very small. Crtstallaria, 472. 



//. Premaxillaries protractile; dorsal spines 7 to 11. 



111. Anal spine single; anal nearly as large as second dorsal; vertebra; 



41 to 44; bones of skeleton very thin. • Ammocrypta, 473. 



mm. Anal spines 2; anal fin small, much smaller than second dorsal. 



Ioa, 474. 

 cc. Parietal region of skull not depressed, more or less strongly convex in cross- 

 section, thus, n ; premaxillaries never protractile ; belly covered with ordi- 

 nary scales; veutrals inserted close together; anal fin rather small, of 7 to 9 

 soft rays, notably smaller than second dorsal, usually with 2 .opines; vertebra; 

 31 to 36, the bones rather firm, 

 n. Lateral line developed, at least anteriorly; dorsal spines 8 to 14. 

 o. Lateral line straight; body rather robust. 

 p. Head naked above. 



q. Dorsal fins large, usually with more than 7 spines. 



Etheo.stoma, 475 



fjq. Dorsal fins small, A'I-10. Alvarius, 476. 



pp. Head completely scaled above. ' Psyuhkomaster, 477. 



00. Lateral line with a slight arch running high anteriorly; dorsals well 



separateil; body slender. 



r. Head scaled above. Copelandellis, 478. 



rr. Head naked above. Boleichthvs, 479. 



nn. Lateral line wholly wanting; fins all very short, only 6 dorsul spines; verte- 



br» 14 -f- 16 = 30. SIiCROPERCA, 480. 



