92 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



teeth, which are found in Clinus, this genus has a narrow line of very minute 

 teeth running longitudinally down the middle of the tongue, communicating a 

 sensible roughness to the touch. Thirdly, the ventrals are more backward, their 

 point of insertion being only a very little in advance of that of the pectorals. 

 Lastly, it is remarkably characterized by having three, or one might almost 

 say four, distinct lateral lines. The uppermost of these lines commences 

 at the posterior angle of the opercle, whence it turns abruptly upwards 

 and runs immediately beneath the base of the dorsal : the second runs 

 along the median line of the body, but does not commence till a little beyond 

 the base of the pectoral: the third commences a little above the insertion of the 

 ventrals, and answers to the upper one, taking its course a little above the 

 anal : there is also part of a fourth, which originates between the ventrals, and 

 joins the third at the commencement of the anal. All these lines are marked by 

 larger and differently formed scales from those on the body, (which last are very 

 minute,) with an elevated tube on each, the tubal pore, however, being most 

 distinct on the middle or second line. In its general form, and in the large 

 number of dorsal spines, this genus resembles Clinus: the form of the head and 

 mouth are for the most part similar; also all the parts of the gill-cover; as well as 

 the branchial membrane, which is six-rayed and free all round. The tags at the 

 tips of the dorsal and anal spines are very conspicuous, and give those fins some- 

 what of a labriform appearance. 



It is not improbable that the Clinus littoreus of Cuvier and Valenciennes, which 

 they have characterized from a drawing and description in the Banksian Library, 

 and which is said to possess twenty-five spines in the anal fin, may belong to this 

 new genus. It is observed by those authors, in reference to its peculiarity in this 

 respect, that such a circumstance, if correct, would be unexampled, and would 

 tend to separate it from the genus in which they have placed it. It is also worth 

 remarking that the C. littoreus comes from New Zealand, the same country as 

 that whence Mr. Darwin obtained the above. 



In the circumstance of having three lateral lines, this new genus seems to 

 have some affinity with Chirus of Steller ; but the scales are not ciliated as they 

 are said to be in this last, neither are the ventrals five-rayed. 



Acanthoclinus fuscus. Jen. 



Plate XYIII. Fig. 2. 

 Form. — Body elongated and compressed ; the depth, which varies but little, one-sixth of the entire 

 length ; thickness in the region of the pectorals rather more than half the depth. Head con- 

 tained very little more than four times in the length. Profile sloping but very little. Snout 

 rather short : mouth protractile, and rather wide : lips somewhat fleshy and reflexed. Gape 

 reaching to beneath the anterior part of the orbit, but the maxillary, which is dilated at its 



