350 THE FLOUNDER FAMILY. 



that the spawning-period was probably not nearer than July, a 

 supposition which Cunningham's remarks corroborate. 



Remarks on Young Topknots. 



In connection with the foregoing are certain curious forms, 

 the early stages of which were found by Mr Holt in May, 1891, 

 during the Survey of the Fishing-Grounds on the west coast 

 of Ireland under Mr Green and Prof Haddon. They are recog- 

 nized by their dense black pigmentation (Plate XIV, fig. 2). 

 At 5'87 mm. the eye.s are symmetrical, snout long, angle of the 

 jaw prominent, the body elongated and the notochord straight. 

 The marginal fins are broad, but without rays, except embryonic 

 in the tail-region. A pre-anal region is present, and the vent 

 opens at the edge. The breast-fins are lobate, and the pelvic 

 fins are rudimentary. One of the most conspicuous features, 

 however, is the presence of a pair of large compressed spines 

 on the external wall of the ear-cyst. The pigment is mainly 

 black, but greenish-yellow is also present over the brain and 

 along the dorsal and ventral lines. A median line of pigment 

 occurs on the belly, and a line of black with a few yellow specks 

 on either side of it. The latter form a loop. Six very distinct 

 pigment-patches occur on the dorsal, and four — not including 

 the hypural — on the post-anal fin. The pigment of the trunk 

 is not broken up into bars. The base of the breast-fin is also 

 pigmented, and grains of the same occur on the sides of the 

 head and jaws, and on the snout'. The largest example 

 measured 1062 mm., and the condition of the eye on the right 

 shows that it is a sinistral form with fin rays, — D. about 80 and 

 anal about 66. Little change had taken place in the pigment, 

 or in the spines over the ear. 



Holt's view that these young forms pertained either to the 

 brill or to the Norway topknot was a reasonable one. The 

 young brill, however, at the stage reached by these specimens, 

 is a larger and thicker fish, the pigment and general outline 

 differ, and it has no spines on the ear-capsules. Holt 

 points out, again, that the fin-ray formula of the Norwegian 

 1 Mr Holt, Tram. R. Dubl. Soc. Vol. v, p. 112, 1893. 



