FISHES. 267 



family with the preceding, but it apparently belongs to a peculiar one — Stylopho- 

 KiD-E — and perhaps is not really related to the typical Taeniosomi. 



Sub-Order XIII. — Xenoptervgii. 



There are certain fishes distinguished by the development of a suctorial apparatus 

 on the breast of a very comj^licated nature. They have been generally approximated 

 to the Cyclopteridoe and Liparididie, simply because they had the suctorial apparatus, 

 and the other fishes had likewise sucking appendages. But the adaptation for similar 

 purposes has been effected in the group now under consideration — the Gouiesocid^ — 

 in a very different way from that exemplified in the lam]>-suckers and their relations, 

 as has been well shown by Dr. Giinther. The suctorial disk is developed chiefly from 

 the skin of the breast, and only formed at its front by the ventrals, which are wide 

 apart. There are no spines in any of the fins, and thus it has not even the technical 

 characteristics of the true Acanthopterygians. Doubtless the parentage of the stock 

 is to be looked for in that great sub-order ; but the divergence of the known forms has 

 been so great that at jjresent it cannot be certaiidy predicated whereabouts to find it. 

 The distinction of the group is sanctioned by modifications of the skull, especially the 

 reduction of the palatal arcade, and the loss of the suborbital ring, as well as by a 

 peculiar development of the several elements of the sho\ilder girdle. 



The Gobiesocidse are mostly fishes having an oblong or elongate coniform body 

 destitute of scales, a depressed head, a single posterior dorsal, an anal more or less 

 opposite, pectorals generally extending downwards along their bases around the front 

 of the suctorial disk, and the suctorial disk entire, or divided into two portions by a 

 transverse fold of the skin. 



Almost all the species are small fishes, most numerous in the tropical or warm tem- 

 perate seas, chiefly living between tide-marks or in shallow water, and generally 

 adherent to stones or rocks by means of the suctorial disk. Several species occur 

 along the Amei'ican coasts, the largest and most common being the Gobiesox or Cau- 

 larchtis reticulatus of California. That species reaches a length of about six inches. 



Sots-Order XIV. — Axacanthini. 



An order or sub-order has been almost universally recognized for the common cod- 

 fishes, and in the same group have been almost universally approximated forms which 

 certainly have considerable superficial resemblance to those fishes, but which anatomy 

 shows to be much less closely allied than has been supposed. The chief distinctive 

 characters of the sub-order (for at most it is nothing more) is the absence of any 

 fenestra or hole in the hypercoracoid or, as it is often called, scapular bone, and its 

 representation only by the inter-space between the hypercoracoid and hypocoracoid. 

 Several families belong to this sub-order, thus defined, and one of them is of very 

 great economical importance. This is the family Gadida'. 



The Gadida are fishes with the caudal portion of the body coniform behind and 

 with the caudal rays precurrent above and below, a sub-median anus, moderate sub- 

 orbital bones, mouth tenninal, or nearly so, and thoracic ventrals. The dorsal fins are 

 variously develo))ed, and the anal, also diversiform, is confined mostly to the posterior 

 half of the length. It will be most convenient to bring them under groups or sub- 

 families. 



