198 Part [11 —Sixteenth Annual Report 
this, and also because of their nutritive qualities, they form one of the 
most important constituents of fish-food existing in the sea; this remark 
applies, of course, to young Entomostracans as well as to the other 
orders of this great class of invertebrata. The minute nauplei, the larger 
megalops, and other stages of crustacean growth, along with embryo 
mollusca, form, no doubt, the principal food of young fishes of all kinds. 
Mr H. Dannevig, in his paper* describing his experiments in the rearing 
of larval and post-larval plaice and other flat fishes, gives some interest- 
ing observations bearing on the value of young Crustacea as fish food. 
The examination of the stomach of large numbers of young fishes at the 
Marine Laboratory of the Fishery Board for Scotland at Tarbert, Loch 
Fyne, during 1886-87, some of the results of which are published in 
the Board’s Fifth Annual Report, also show that the importance of 
young Crustacea as fish food has long been recognised, and, as a matter of 
fact, their importance in this respect cannot well be overstated. It is 
evident, therefore, that the study of the distribution of these miniature 
forms, and of the influences that govern their increase or decrease, as 
well as the investigation of their life-histories and development, are well 
within the scope of scientific fishery work. 
The records of miniature Crustacea included in the lists of tow-net fauna 
that form the basis of this paper refer chiefly to the young of various 
species of the Decapoda. Among the more common of the larval 
Decapoda included in the tow-net gatherings are those of Portunus (or 
swimming crabs), of Porcellana longicornis, of the Eupaguride (or soldier 
or hermit crabs), and of Nephrops norvegicus (the ‘‘ Norway lobster”). 
The young of Galathea (or what some fishermen call the ‘ bastard 
lobster”) and of various shrimps, such as Crangon and Pandalus, which 
are at times more or less frequent, are also included among these records 
under the general name of young or larval Crustacea. Young Schizopoda, 
as such, are specially referred to in the lists only when they happen to be 
common or abundant; at other times they are included with the young 
Decapods. The larve and young of the Barnacle are more frequently 
recorded separately, but they also are sometimes included with the others, 
and the table of distribution comprises the records of all the three 
groups. The total number of records referring to young and larval 
Crustacea is about three hundred and forty, and an enumeration of them 
is contained in the annexed Table. This Table shows that in some 
respects the distribution of the immature Crustacea is somewhat similar 
to that of the Ceelenterata. If, for example, the total number of records 
of immature Crustacea for each of the three inner stations be compared 
with those for the three outer stations, they will be found on an average 
larger than the others, though this difference is not so marked as is the 
case with Ccelenterata. 
It will also be observed that the yearly maxima of records for the 
various stations are not so regular, and also that the larger of the monthly 
records occur during the summer months. 
* Fifteenth Annual Report of Fishery Board for Scotland. Partiii. Pp. 175-193. 
| TABLE. 
