364 



U. 8. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



List of specimens,. 



Family EMBIOTOCOIDAE or HOLCONOTI, A 



erass. 



The ichthyic group, of which we propose now to treat, is one that has created the most vivid 

 interest, not only amongst ichthyologists, but likewise among naturalists at large, when the 

 singularity of their habits was announced to the world. 



In their general form and external appearance these fishes have nothing peculiarly striking. 

 Their aspects remind us of fishes familiar to all, such as the sunfish, pond-perch, or bream 

 (Pomolis), of our fresh water streams, ponds, and lakes ; and the sheepshead and porgee 

 (Sargus), of marine habits. 



Their body is much compressed, oval, or elliptical, covered with scales of moderate size, 

 cycloid in structure, and thus widely distinct from those of both percoids and sparoids, to which 

 Pomoiis and Sargus belong. The cheeks and opercular apparatus are covered with conspicuously 

 developed scales. The opercular apparatus, itself, wants either spines or serratures. The 

 branchiostegal rays are five or six in number, generally concealed under the lower edge of the 

 opercular apparatus. The branchial aperture of either side meets its fellow under the throat, 

 leaving no room for an isthmus. The mouth, variable in size according to the genera, is sur 

 rounded by well developed lips, either fleshy or thin, a character which they bear in common 

 with the labroids (Tautog, Chogset, or Conner, of our eastern coast), to which family these fishes 

 are intimately related. The lip surrounding the lower jaw is either free all round or else united 

 by a frenum to the symphysis of its jaw. The upper jaw is exclusively formed by the inter- 

 maxillaries, which, together with the maxillaries, situated immediately behind, possess a greater 

 or lesser degree of protractility according to the genera. Teeth exist upon the intermaxillaries, 

 the dentaries, and pharyngeals ; the maxillaries, the vomer, and the palatines, are toothless. 

 On the pharyngeals the teeth are pavement-like ; on the jaws they are conical or sub-conical, 

 slightly curved inwardly, and disposed, either upon a single or upon a double row, on both jaws. 

 Again we may observe a double row on the upper jaw and a single row on the lower one. The 

 scales, we have already stated, are cycloid in structure, sometimes deeper than long ; at others, 

 longer than deep, provided with radiating furrows upon their anterior section only. As to the 

 fins, there is a long and unique dorsal, anteriorly spiuous, sheathed at its base by one or more 

 rows of scales, separated from those of the body by a linear furrow, not extending, however, 

 along the whole base of that fin. The spinous portion alone is capable of being folded back 

 wards, and partly to disapppear between the sheath, no doubt a provision of nature to assist 

 the process of parturition. The anal varies in length and depth according to the genera and 

 species, but is always provided anteriorly with a few short spinous rays. Its anterior soft rays 



