178 Part IIT.—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 jfinmarchicus. 
Calanus jinmarchicus 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 IV.; 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, 
