202 



Part III. — Twenty-second Annual Revort 



8. The Sharp-Tailed Lumpenus (Lumpenus lampeti'iformis.) 



Fairly large numbers of this fish are taken in the small meshed-net 

 around the otter-trawl, more especially in the deeper parts of the Moray 

 Firth, as off Kinnaird Head, and at the mouth of the Firth of Forth, and 

 some of the collections have been measured. The best of these was one 

 got at Station V. in the Firth of Forth, on 10th May, 1901, which com- 

 prised 255 specimens. They ranged in length from 127mm. to 345mm. 

 (5 - 13| inches). The measurements, grouped in half centimetres, are 

 appended, and the curve is given in Plate XI. It is apparent 

 from these that at least three series, and possibly five, are represented in 

 the collection. What appears to be a first series is indicated by two 

 specimens, measuring 127mm. and 128mm., the next size being 138mm. 

 On the 16th May, on the same ground, a still smaller one was captured, 

 viz., at 123mm., the next measuring 172mm. In a haul on 31st August, 

 off Sumburgh Head, in sixty-five fathoms, the smallest I have obtained 

 was taken, viz., 84mm. (3^ inches), the next largest in the small 

 collection being 154mm. I am inclined to think that the specimens in 

 the Forth collection referred to were the larger members of an early 

 series, the smaller individuals probably escaping through the meshes of 

 the net ; the specimen at 138mm, might also belong to this series. 



The second group begins at 138 or 146mm., its division from the third 

 series being fairly well defined at 190mm. The range is thus 52mm., the 

 average size of the thirty-three specimens, 167"8mm. (6J- inches), and the 

 mean, with the first-named limit, 164mm., and with the series beginning 

 at 146mm., 168mm. 



The next group begins at 197mm., and it appears to terminate at 

 263mm., a range of 66mm. In the curve based on the half-centimetre 

 grouping of the measurements, there is a depression at 23cm. ; it does not 

 seem, however, to represent a division between series, but only irregular 

 representation. The number of fishes composing the second series was 

 127, the arithmetical average size was 235 , 2mm., and the mean 230mm. 



The next series begins at 264mm., and extends to 312mm., a range of 

 48mm. It comprised seventy-eight fishes, whose average length was 

 288 -9mm., the mean size being 288mm. 



The other fifteen fishes in the collection probably belong to an older 

 group. They measure from 315mm. to 345mm., the average size being 

 325 - 7mm., and the mean size 330mm. 



The averages and limits above given are based on the supposition that 

 five series are represented ; but on the assumption that the smaller fishes 

 belong to the same series as the second group, then the extent of the 

 latter would be from 127mm. to 190mm., a range of 63mm., a^id the 

 average size of the thirty-five fish would be a little less, viz., 165'4mm., 

 the mean being 158*5. If the fifteen larger fishes be included with the 

 preceding series the range would be extended from 264 to 345mm., a 

 difference of 81mm. — obviously too great — and the average size would 

 become 294'9mm., the mean being 304-5mm. Looking at the curve there 

 seems little doubt of the presence in the collection of members of a fourth 

 series, and scarcely less of the presence of the early one. 



The amount of annual growth between the series as determined above 

 are as follows : — 



1st to 2nd. 



Mm. - 40-3 

 Inches, - If 



2nd to 3rd. 

 67-4 



3rd to 4th. 

 53-7 



4th to 5th, 

 36-8 



