226 



Appendices to Fourth Annual Report 



leaving the fins tightly pressed against it. The fish would remain in this 

 position for hours if not disturbed. It has already been stated that the 

 basal portions of the dorsal and anal fins are different in structure from 

 the remaining parts. The object of this is now obvious. When the fish 

 is in the position described a constant current of water is made to pass out 

 from the branchial chamber on the lower side, along the channel caused 

 by the arching of the body, by a rapid movement of the basal portion of 

 these fins. The motion is usually incessant and very quick, resembling 

 that of cilia. Occasionally when there are particles of debris suspended in 

 the water these may be seen to pass rapidly out of the branchial chamber, 

 and then to travel more slowly along the body axis, and finally to be 

 drawn out with a rapid whirl by the action of the accessory portions of 

 the dorsal and anal fins. During normal respiration the lower law shows 

 little or no movement, and the dilation and contraction of the opercular mem- 

 brane on the upper side is scarcely noticeable. The accessory portions of 

 the vertical fins appear then to be specially constructed to aid in the 

 respiratory function. So far as I know, this peculiar adaptation is not met 

 with in any other genus of British Fishes. In Z. punctatus there are 

 similar accessory portions to the vertical fins, and although I have not 

 seen this species alive, it is to be presumed that they serve the same purpose. 



I have to thank my friend Mr W. L. Calderwood for the figure of this 

 species, which is a life-size representation of the largest Tarbert specimen 

 (Plate IX.). A drawing of the accessory portion of the vertical fins, as 

 seen from the under surface, will also be found on the same plate. 



A specimen, caught in 10 fathoms on the 13th of June, was a ripe 

 female, and measured 5 inches in length. A number of eggs were laid in 

 confinement, but as we had only the one specimen at the time, they were not 

 fertilised. The eggs are very buoyant, and rise at once to the surface of 

 the water. The eggs are quite transparent and contain a small yellowish 

 oil-globule. I had no means of measuring the living eggs, but those pre- 

 served measured about *96 mm in diameter. 



This species appears to be very rare all around the British Isles. 

 Fleming recorded one specimen from Zetland, and Johnston mentions it 

 as occurring on the Berwickshire coast. In 1860 Ferguson took one off 

 Redcar, in Yorkshire ; and specimens have also been taken off Plymouth, 

 Weymouth, and the Cornish coast. One specimen was taken in Belfast 

 Bay in 1838, and two others are recorded from the same locality in 1844. 



There is another specimen in the collection of the Fishery Board, pro- 

 bably from the West Coast, but I do not know when or where it was 

 captured. 



10. Zeugopterus punctatus (Bl.). — This species is met with much more 

 frequently than Z. unimaculatus, but still it is by no means common, at 

 any rate around the Scottish coast. A specimen was obtained in the 

 Firth of Forth last June, and forwarded to the Central Laboratory by Mrs 

 Stewart of Leith. The fish measured 7 inches in length. Another 

 specimen has been forwarded by the Fishery oflScer at Montrose. It was 

 caught by a steam trawler about 8 miles S.E. of Wick Bay on the 24th of 

 February 1886. The bottom was sandy and the depth of water about 32 

 fathoms. The specimen is 7^ inches in length. 



11. Pristiurus melanostomus (Raf.), Black -mouthed Dog-fish. — This 

 species is common in the Mediterranean, but has not been often recorded 

 around the British Isles. Specimens were sent to Yarrell from the West 

 Coast of Scotland (Malcolm). Edward is led to believe that this species 

 occurs occasionally off Banff ; and a specimen was taken at Polperro, in 

 Cornwall, in 1834. These are all the localities given in Day's British 

 Fishes. 



