THE LEPADOGASTER FAMILY. 195 



The Lepadogaster Family. 



The Bimaculated Sucker. {Lepadogaster bimaculatus, 



Donov.) 



This fish is rather more characteristic of the southern and 

 western than the eastern shores, though it is by no means rare 

 on the latter or in the north of Scotland. The eggs are 

 deposited towards the end of June and in July (being most 

 common in July and August), inside empty bivalve shells, such 

 as Veiius, Pectunculus, Solen, and Pecten, and also along with 

 L. Decandolii at Guernsey, in the interior of the hollow basal 

 swellings of the curled tangles, the adult fixing itself beside the 

 eggs by means of the sucker. The eggs (Plate II, fig. 5) are 

 stated by Mr Holt to have a long diameter of 1*37 mm. and a 

 short one of 1-08, while the height is '68 mm. The preserved 

 eggs have a long diameter of 114 to 1'37 mm. and a short 

 one of -914 to 1'2 mm., while the height is •64 mm. These 

 dimensions thus agree with those of Mr Holt — taking the 

 contraction caused by spirit into consideration. They are 

 placed separately in most cases, though not with regu- 

 larity, inside the shells, attached by a flattened surface of a 

 peculiar structure. On the irregular surface of the cavity of 

 the tangle they were somewhat close to each other; indeed, 

 two or three were occasionally lifted together by the basal 

 secretion, and they covered all the available surface. The 

 attached or flattened surface is coated by an adhesive secretion ; 

 the micropyle, as Mr Holt in his careful description observes, 

 being in the middle. He found the aperture closed, as was 

 the case also in those examined here, the disks or bosses of 

 the cilia or long papillae of attachment occurring over it. A 

 fine fibrillar secretion occurs over the whole of the attached 

 surface, the fibres radiating from the micropyle outward towards 

 the marginal fringe. The surface of the capsule (zona) in this 

 region is closely studded all over with distinct pustule-like 

 disks or bosses from which cilia or processes project, the tip 

 being often bifurcate and ending in long filaments. These and 



13—2 



