566 contributions to north american ichthyology iv. 



Family XCI.— SCI^NID^. 



{The CroaJcers.) 



Body compressed, more or less elongate, covered with rather thin, 

 ctenoid scales. Lateral line continuous, extending on the caudal fin. 

 Head prominent, covered with scales. Bones of the skull cavernous, 

 the muciferous system highly developed, the surface of the skull, when 

 the flesh is removed, verj" uiiCA^en. Chin usually wdth pores, sometimes 

 with barbels. Mouth small or large, thie teeth in one or more series, the 

 outer of which are sometimes enlarged; canines often present. No in- 

 cisor nor molar teeth ; no teeth on T,'omer, palatines, pterygoids, nor 

 tongue. Maxillary without supplemental bone, slipping under the free 

 edge of the preorbital. Premaxillaries protractile, but not very freely 

 movable. Nostrils double. Pscudobrauchise usually large, present in 

 all our genera. Gills 4, a slit behind the fourth. Gill-rakers present. 

 Branchiostegals V. Gill-membranes separate, free from the isthmus. 

 Lower pharyngeals separate or united. Preopercle serrate or not. 

 Opercle usually ending in two flat points. Dorsal fin deeply notched, 

 or divided into two fins, the soft dorsal being the longer, the spines 

 depressible into a more or less perfect groove. Anal fin with 1 or 

 2 spines. Ventral fins thc-racic, I, 5. Pectoral fins normal. Caudal 

 fin usually not forked. Ear-bones very large. Pyloric coeca usually 

 rather few. Air-bladder usually large and comx^licated (want ing in Alen- 

 ticirrus). Most of the species make a peculiar noise, called variously 

 croaking, grunting, drumming, and snoring. This sound is sui)posed 

 to be caused by forcing the air from the air-bladder into one of the lat- 

 eral horns. Carnivorous. An important family of about 25 genera and 

 126 species, found in all warm seas, one species being confined to fresh 

 waters. Many of them reach a large size, and nearly all are valued for 

 food. 



(ScicenidoB Giinther, ii, 265-318.) 



* Dorsals contiguous, the second dorsal much larger than the anal. 

 t Vertebrae about 10 -(-14. {Sciceninw.) 

 t Lower jaw included. 



$ Lower pharyngeals fully united, with paved teeth ; second anal spine very large. 

 a. Lower jaw without barbels. (Fresh-water species). Haploidoxotus, 2l>4. 

 aa. Lower jaw with several small barbels. (Marine species). PoGOXi as, 295. 

 §§ Lower pharyngeal bones distinct. 



b. Lower jaw without barbels; anal spines 2. 

 c. Teeth well doveloi^ed, persistent in both jaws Sci^na, 296. 



