178 Part III. — Sixteenth Annual Report 



A few of the species named above are found occurring with more or 

 less frequency in nearly all the lists of tow-net invertebrates, but the 

 larger number of them were infrequent or rare, and it is those only that 

 are of numerical importance that need be specially referred to here. The 

 first of them that I propose to notice is Calanus finmarchicus. 

 Calanus finmarchicus is, because of its numbers and its general distri- 

 bution, one of the most important of the group to which it belongs, at 

 least in the British seas. Being usually so numerous, it no doubt 

 furnishes a rich supply of food to the young of all kinds of fishes, 

 and, as a matter of fact, it frequently forms the principal food of the 

 herring. This species is, as a rule, usually more numerous than the 

 other pelagic Copepods, and it occurs at times in considerable abun- 

 dance in the estuary. Its distribution, as indicated by the tow-net 

 records, is as follows : — In 1889 Calanus is recorded twice for Station I. 

 in January ; once in July, August, October, and November for Station 

 III. ; once in January, July, and August for Station IY. ; once in 

 January, May, June, August, and September for Station V., while for 

 the same station in November Calanus is recorded as abundant in the 

 surface and frequent in the bottom tow-nets ; for Station VIII. it is 

 recorded once in January, twice in June and July, once in August, and 

 once in November ; for Station IX. there are two records in June, one 

 in August, and two in November. In the surface tow-net record for 

 November Calanus is described as abundant, and as common in the 

 bottom tow-net. 



In 1890 the records of Calanus for Station I. are two in February, 

 March, April, May, July, October, and November, and one in December. 

 It is described as abundant in one and common in four of these 

 gatherings. The records for Station III. are two in February, March, 

 April, May, July, October, and November, and one in August ; for 

 Station IV. there are two records in March, May, November, and 

 December, and one in February, April, July, August, and October. 

 The records for Station V. are two in February, March, April, May, 

 September, October, November, and December, and one in July. For 

 Station VIII. there are two records in March, April, May, September, 

 and December, and one in February, July, and October ; while for 

 Station IX. there are two records in March, April, May, October, and 

 December, and one in February, July, and September. The records for 

 Calanus in 1891 are for Station I. two in February, March, April, 

 May, June, and August, and one in January, July, October, and 

 November. For Station III. there are two records in February, April, 

 May, June, July, and December, and one in January, August, September, 

 October, and November. For Station IV. there are two records in 

 January, February, March, April, May, June, and October, and one in 

 August and November. The records for Station V. are two in February, 

 March, April, May, July, October, November, and December, and one in 

 June and August. Station V. having been trawled twice in October 

 adds a third record for that month. There are two records for Station 

 VIII. in February, April, May, June, and November, and one in July, 

 August, September, and October ; while for Station IX. there are two 

 records in February, May, June, July, August, and November, and one 

 in April, September, and October — making ninety-seven records in all for 

 1891. The number of the records of Calanus for 1892 is about equal to 

 that of the previous year. Those for Station I. are two in April, May 

 and December, and one in January, February, March, July, September, 

 and November. For Station III. there are two records in February, 

 March, April. May, November, and December, and one in January, July, 



