SORTATION. 23 



In the " eyes right " group there are also four British genera, 

 divisible into two in which the jaws are alike on both sides, and 

 two in which they are larger on the blind side. Those in which the 

 jaws are similar on both sides are Hippoglossoides, represented by 

 H. limandoides, the long, rough dab or lemon sole north of the 

 Forth distinguished by the straight lateral line and rough scales, 

 and, above all, by its size (which never exceeds a foot and a 

 quarter) from Hippoghssus, in which the lateral line is curved, the 

 scales smooth, and the size enormous, for its only British repre- 

 sentative is H. vulgaris, the halibut, narrowest and largest of the 

 flat-fish, which is commonly five feet long, and has been known to 

 exceed twenty. 



The other two are Pleuronectes and Solea, the latter distinguished 

 by having no teeth on the upper side, instead of a few feebly 

 developed, by the snout projecting beyond the jaws, instead of the 

 mouth being at the end of the snout, and by having a sort of beard 

 of short projections from the skin on the under side of the head. 

 Of Pleuronectes the species on our list are the flounder, P.flesus, with 

 tubercles along the bases of the fins ; the dab, P. limanda, with a 

 curved lateral line; the witch, P. cynoglossus, with no spots, the 

 smear dab (another of the lemon soles), P. microcephalus, with dark 

 spots, and the plaice, P. platessa, with orange spots, and having 

 tubercles on the head. Some people are said not to know a turbot 

 from a plaice ; they have only to remember that one has the eyes to 

 the left, the other has the eyes to the right. Some are said not to 

 know a sole from a lemon sole : the only way out of that difficulty is 

 to know what a sole is like, the lemon sole being what may be called 

 various, and generally but a somewhat distant relative. Of the soles 

 there are only four species (i) the solenette, Solea lutea, which is 

 not more than five inches long, never used for food, and has black 

 rays, like stripes, on its fins ; (2) the thickback, 5. variegata, which 

 is chestnut brown on the upper side, with five broad, dark bands ; 

 (3) the sand sole (perhaps the original lemon sole), S^-kiscaris, which 

 has the lower nostril larger than the other, and is orange in colour, 

 with dots and specks ; and (4) the common sole, S. vulgaris, in 

 which the nostrils are alike, and the colour blotchy brown, with a 

 black spot at the outer end of the pectoral fin. To sum up our 

 " eyes right " division, we stand thus : 



Jaws alike on both sides 



Lateral line straight Hippoglossoides, 

 Lateral line curved Hippoglossus. 



Jaws not alike on both sides 



Mouth at end of snout Pleuronectes. 

 Snout curving beyond mouth Solea. 



With the soles we end our list of horizontals, and are face to face 

 with the many more verticals, to one of which our specimen belongs. 

 These we can sort out at once according to their tails. 



There are half-a-dozen genera in the British list which are with- 

 out a caudal fin ; to dispose of these is to clear the way. Their shape 

 is enough to guide us. In two the body tapers from a large head ; 

 these being Chimara, in which the tail becomes a long filament, and 



