36 A. E. HEFFORD. 



and the yellow and black pigmentation typical of G. merlangus. A third 

 whiting egg was taken on 12th July, about 1| miles south of Eame 

 Head. The diameter was 1"12 mm. and the length of the larva within 

 the first day 3"58 mm., the distance from snout to anus being 1*58 mm. 

 The fewness and infrequency of the appearance of whiting eggs in my 

 collections are undoubtedly due to the fact that our tow-nettings have 

 not been taken anywhere near the off-shore breeding haunts of the 

 species at the time of their spawning season. 



Onos, Eisso ( = MoTELLA, Cuvier). The Recklings. 



It is an open question whether our knowledge of the occurrence of 

 the members of this genus in the Plymouth neighbourhood is complete 

 and exact, but certainly the presence of more than one species has com- 

 plicated the task of fully identifying the rockling eggs, which have long 

 been well known as occurring here in abundance. The most common 

 species found here isO.mustda, L., and 0. tricirratus (Bloch) is also known, 

 while Holt (lid, p. 143) speaks of " the undoubted existence in the dis- 

 trict of M. cimhria and M. maculata, and possibly of other forms which 

 may require specific distinction." I have no personal knowledge of the 

 occurrence of the two latter species, but I may mention that a form 

 identified as Motclla fusca, Moreau, by Garstang and Balfour Browne was 

 taken in April, 1901, on the shores of Plymouth Sound.* 



However, the problem of denoting the species of the pelagic ova 

 commonly occurring at Plymouth, is mainly one of deciding which other 

 species besides the abundant 0. mustcla are represented. My task of 

 identification has been aided by the recent publication by Ehrenbaum 

 (5c, p. 237, and 5d, p. 284) of descriptions of the ova and larvae of 0. 

 mi(stela, L., and 0. cinibrins, L. In regard to the latter species I need 

 only say that it does not appear to be represented in my samples of 

 ova, nor do I know of any record of the occurrence of the adult in this 

 district."!" 0. mustcla, on the other hand, is the prevailing species, and 

 what I was led to expect, from the abundance of the fish in Plymouth 

 Sound, is confirmed by comparison with Ehrenbaum's description of the 

 egg and larva of the species. He gives the average diameter of the ova 

 of 0. mustela as varying (off Heligoland) from 0"878 mm. in February to 

 0"736 in June, and the peculiar pigmentation of the late embryo and 

 early larva as the chief diagnostic character (at least as far as dis- 

 tinguishes it from 0. cimhrius), viz. the arrangement of the post-anal 



* Journ. M.B.A., N.S., VI., p. 626. 



t A small immature specimen of 0. cimhriKS was, however, taken in Whitsand Bay on 

 the 3rd Marcli, 1910, wliich is, I believe, the first record of the species for the Plymouth 

 neighbourhood, 



