Holt — On the Eggs and Law ce of Teleosteans. 447 



GOBIESOCID^. 



Lepadogaster bimaculatus (Donov.). The Doubly-spotted Sucker. 



(PI. XLVII., figs. 1-7.) 



On the 12th June a whelk-shell was obtained in the trawl in Clifden Bay, and 

 proved to contain a specimen of Lepadogaster bimaculatus. On breaking the mouth 

 of tlie shell a number of ova were revealed, attached to the inside of the last 

 whorl near its commencement. 



The shape of the ova (figs. 1-3) is remarkable. They are not globular, as 

 described by Hyndman,* but ovoidal and abruptly truncated inferiorly (fig. 1), 

 having something of the shape of an ordinary dishcover. The length is 1-37 mm., 

 the breadth 1'08, and the height "68 mm., but these dimensions, as also the 

 contour, are subject to slight variations. There is a single, large, colourless 

 oil-globule {o.g.) of 24 mm. M'Intosh and Prince [op. cit., p. 672) noted that the 

 zona shows verj^ evident punctures. 



The flattened under-surface of the egg (fig. 4) adheres to the shell by means 

 of a remarkable attachment apparatus. The micropyle is central, and is closed in 

 the somewhat advanced stages studied. Its site is visible from below as a minute 

 clear, oval area [mi.), from the edges of which numerous interlacing fibrils radiate 

 outwards, forming by the cohesion of their distal ends a structure resembling a 

 shallow circular basket with a thickened rim (r.p.), from which are given off very 

 numerous fine filaments (fit.) of considerable length. It is evident that these fila- 

 ments have an adhesive function in the freshly-extended ovum. In favourable 

 preparations it is seen that this plate-like structure is continuous with the rest of 

 the zona only in its centre, i. e. around the micropyle (77ii.). In addition to this 

 central apparatus the whole of the flattened surface of the zona is studded by 

 numerous short, stout, rod-like bodies (rd.), having rounded bases springing from 

 the zona, whilst their distal extremities, which are directed towards the periphery, 

 bifurcate, and thereafter taper very rapidly into long and extremely fine adhesive 

 filaments (//., fig. 4) similar to those of the central structure. These can be seen, 

 in an isolated egg viewed from above (fig. 3), projecting as a fringe (Jil.) beyond 

 the edges of the inferior surface. The zona is of moderate thickness, and there 

 appears to be no layer external to it. Treated with picro-carmine it takes on the 

 carmine stain faintly, whilst the attachment apparatus is entirely unaffected by it, 

 with the exception of the thickened rim (fig. 4, r.p.) of the central structure. This 



* This observer gives about tV inch, as the diameter. Day, " British Fishes," vol. i., p. 193. 



