94 



Part III. — Seventeenth Annual Report 



large amount of dependence on size is necessary, since such a diagnostic 

 feature as the pigment of the embryo is obliterated to a large extent. 

 Holt* believes an egg measuring l^-l^mm., captured at Plymouth, to 

 be the egg of a large Pollack. 



Miller's Topknot (Zeugopterus punctatus, Bl.). The size of the egg of 

 this species is given by M'Intosh and Prince f as l*05mm. in diam., O.G. 

 •2mm. An egg measuring Llmm., O.G. ^tnm., I have regarded as 

 belonging to this species. 



Species A (Phrynorhombus unimaculatus T). An egg measuring 

 •9-'95mm. in diam., O.G. 'IT-'^mm., occurred frequently in the tow- 

 nets in May, and from time to time in June, July, and August. Holt § 

 measured the ripe eggs of this form, and found them to be , 92- , 93mm. in 

 diameter. Cunningham % records that eggs were obtained by Brook in 

 Loch Fyne in June from a female P. unimaculatus. They measured in 

 diam. '96mm., and had a small yellowish oil globule. The eggs of 

 Rhombus norvegicus are not very ditferent from those of P. unimaculatus, 

 but so far the former species has not been recorded from Loch Fyne. 

 Holt* discusses the relationship between the eggs of the three Topknots. 



Species B (Arnoglossus laterma, Gthr.). Egg measuring , 65-'7mm., 

 O.G. "15. Holt || obtained ripe ova of this species. He found them to 

 measure •675-*690mm. in diam. (O.G. '14-'15mm.) in one case, in June, 

 and *75-*76mm. (O.G. , 12-*13mm.) in another case, in July. Ehren- 

 baum % had previously described an egg taken in the tow-net as belong- 

 ing to this species. The egg obtained in Loch Fyne was very common 

 in June and July, and occurred also in August. It was obtained quite 

 close to the surface in greatest numbers, but also occurred down to a 

 depth of 10 to 15 fathoms. 



Species C, D, E. These eggs measured respectively — C, 1*2 and 

 l'25mm., O.G. '2mm.; D, M7mm, O.G. -15mm.; E, -9mm., O.G. 

 •27mm. Four eggs of C were found — two in April and two in May. 

 One each of D and E were noticed. 



Species F (Ctenolabrus rupestris, L. ?). This egg, which measured 

 •67-'72mm., was obtained in June and July. It has no oil globule, and 

 very probably is rightly referred to Ctenolabrus rupestris (Holt**). This 

 form is common in Loch Fyne. 



Species G. The egg labelled G in the Tables measured 1*12-1 '16mm. 

 in diam. (O.G. *3mm. and over). It resembles very much the egg which 

 I have diagnosed as that of the mackerel, differing from it slightly in 

 diameter. It was captured in Loch Fyne in April, June, and July. 



Bib (Gadus luscus, Will). The eggs which have been regarded as 

 belonging to this species measured, on the average, l*07mm. diam. 

 A considerable number of eggs measuring exactly l'07mm. were captured. 



On the Occurrence of the Eggs. 



The months in which the largest numbers of eggs were found in Loch 

 Fyne are March, April, May, and June. The following Table shows the 

 number of eggs for each month : — 



* Journal Mar. Biol Assoc., vol v. No. 2, p. 131. 



f " Development of Teleostean Fishes." Trans. Roy. Soc. Eclin., vol. xxxv., pt. iii. 

 X Cunningham, "Marketable Marine Fishes," 1896, p. 277. 

 §Holt, Journal Mar. Biol. Assoc., vol. v., No. 1, p. 46. 

 || Journal Mar. Biol. Assoc., vol. v., No. 1, p. 49. 



HEier u. Larven von Fisch. d. deutsch., Bucht. Wissenschaftliche Meeresunter- 

 SHchungen top. der Biologischen Anstalt auf Helgoland, neue Folge, 2ter Bd. Hft. i., 1896. 

 ** Jour. Mar Biol. Assoc., vol. v., No. 2 p. 124. 



