Gatty Marine Laboratory ^ St. Andrews. 255 



runs from this forward to the base of the pectoral, thus 

 resembling a miniature duplication of the former. The body 

 is now variegated with reddish in the males, pale patches 

 occurring alons; the dorsum. The ventral surface seems to 

 be pale. 



At 25 millim. the colours in a young male from St. An- 

 drews in June are even more brilliant, the bright red of the 

 eyes and the sides of the body being characteristic. The 

 anterior margin of the first division of the sucker is now flat- 

 tened out and the papilla on the surface less distinct, while^ 

 the marginal ones are flattened and more membranous. The 

 accessory flap on the posterior half of the second division is 

 united with the margin of the sucker (a feature, it may be, 

 characteristic of the sex), so that there is no difi'erentiation 

 between them. The vent showed only longitudinal rugse 

 with the long median papilla posteriorly. 



In July forms of 26 and 32 millim. were obtained, and they 

 seem to be the continuation of the former series. The chief 

 change is the increase of the fleshy folds of the lips superiorly 

 and inferiorly. The latter form a semicircular flap on each 

 side, with a posterior continuation, the former having the 

 shape of a broad and continuous flap. In the females the 

 distinction between the margin of the posterior division of 

 the sucker and its broad accessory flap is present. The 

 papillae along the front margin of the anterior division are 

 also distinct in the same sex. 



In August specimens of 22, 25, and 33 millim. from Loch- 

 maddy, North Uist, are in the collection. The smallest is 

 thus only the length of that from St. Andrews in February, 

 so that either the specimen had grown little or had been 

 hatched very late the previous season, unless we are to 

 suppose that very early deposition of ova occurs in the Outer 

 Hebrides. The former is the more probable. 



Adults of 53 and 54 millim. for females and 48 millim. for 

 males are met with the same month, so that they would 

 appear to be at least in their second year. The chief sexual 

 distinctions externally appear to be, in the male, the greater 

 breadth and more membranous condition of the frilled border 

 in front of the anterior division of the sucker, thus giving a 

 larger surface. Similarly the broad frill behind the posterior 

 division of the apparatus is increased, and its folds have not 

 the regular and definite pattern seen in the female. More- 

 over the frill is indistinctly separated from the sucker proper. 

 The latter, in short, has no free rim, but runs into the frill. 

 The testes of the male are small and compact, like those of 

 the shanny. 



