Gatty Marine Laboratory ^ St. Andrews. 251 



surface behind the ventrals shows minute soft papillae scattered 

 over the surface, the precursors of the hispid processes of the 

 next stao;e. At this stage, therefore, the young lumpsucker 

 is armed at most points, a condition of great importance 

 during its more or less pelagic existence. 



During August the captured specimens (in spirit) range 

 from 13*5 to 35 millim., most being above 20 millim. Large 

 numbers are procured in the salmon stake-nets off rocky- 

 borders *, the young lumpsuckers adhering to sea-weeds 

 which are stranded on the ropes, while some are procured in 

 the ordinary bottom-nets. At 35 millim. the rows of hispid 

 tubercles are more pronounced than in the previous stage. 

 The first five of the third row are very large, the hardened 

 distal region being more or less conical, with a pectinate crest 

 of spines which have a slight inclination backwards. Each 

 hardened tubercle moves freely on the softer skin around it. 

 The most evident change, however, and it is one which 

 appears at 31 or 32 millim., is the appearance of minute 

 spinous processes on the skin between the larger rows of 

 tubercles on the upper lateral regions and on the flattened 

 surface behind the ventral sucker, as well as all over the head, 

 the only area apparently free from them being the abdominal 

 wall between the prominent third row and the lateral ventral 

 series, tiie tip of the spines of which also present a slight 

 inclination backwards. The double row of spinous tubercles 

 behind the dorsal fin have increased in size, and form an 

 eflScient protection to the tip of the former when adpressed ; 

 and probably this is important, since the projecting fin would 

 otherwise be readily seized by a predaceous fish. Three 

 spinose tubercles occur on the lower edge of the opercular 

 region. In contrast with the smooth flattened tubercles of 

 the adult, therefore, the young lumpsucker is remarkably well 

 armed. 



Of the subsequent stages of this species the following may 

 be given, viz. 2j inches on June 1st t, probably a small 

 example of the last year's brood ; 5j inches in July ; 7 inches 

 in August ; and Q^q inches in December (covered with Caligi) 

 — all these indicating the growth of upwards of a year, tiie 

 latter example probably being about eighteen or nineteen 

 months old. The sexual differences at an early age have not 

 yet been fully worked out, and therefore it would be premature 

 to draw conclusions on the subject. 



* For example, oS. the East Rocks at St. Andrews, from which many 

 interesting specimens have been presented by Mr. Turbyne. 



t Vide a useful table by Mr. J. K. Tosh, M.A., B.Sc, Twelfth Ann. 

 Rep. Fishery Board, pt. iii. p. 333. 



