25 8 BY THE DEEP SEA. 



and identifying species. We have introduced the names of 

 these already, but we think it would be an advantage to repeat 

 them here, and then to use them throughout the remainder 

 of this chapter. 



The Dorsal fin is on the back ; if more than one they are first dorsal and second dorsal. 



The Pectoral fins are a pair having their origin just behind the gills. 



The Ventral fins are a pair on the belly, behind and below the pectorals. 



The Anal fin is single, in the middle line of the underside between the vent and the tail. 



The Caudal fin is the termination of the tail, and the form of this is very important. 



The Rock Goby has two dorsals, the first with six rays de- 

 creasing in length as they get further from the head; the 

 second with fifteen rays of equal length. The pectorals are 

 rounded behind ; so are the ventrals, which are united by a 

 membrane. The anal fin is just under the second dorsal, if 

 we reckon from the tail forwards, but the second dorsal is 

 longer than the anal. The space between the dorsal and anal 

 fins is occupied by eleven or twelve lines of scales. Full- 

 grown specimens vary from six to nine inches in length. 



The species figured in our illustration (page 257) is the Little 

 Goby (G. minutus], a fish from two to three inches in length, 

 of a yellowish ground colour minutely stippled with brown, its 

 sides alternately streaked with long and short dark stripes. 

 Dorsal fins two, the first rounded, narrow from back to front ; 

 the second wide from back to front, and with slightly concave 

 outline. It appears to be more at home on the sandy than 

 the rocky shore. 



In pools that are lavishly decorated with hanging weeds we 

 may find a number of pretty fishes of a clear green or a rich 

 brown colour. They are the young of the Corkwing Wrasse, 

 or Rath, as Cornish fishermen term it (Crenilabrus melops], a 

 species that grows only to a length of six or seven inches. 

 The Wrasses proper (Labrus), of which we shall have some- 

 thing to say directly, are distinguished by the oblong form of 

 body, by having the gill-covers laid over with scales, and by 



