366 Mr. A. Scott on Scolecithrix hibernica. - 



that lias been bestowed upon fish-food, of which Crustacea 

 form a not inconsiderable part ; for it is owing very much to 

 these investigations that the majority of the additions to the 

 marine and freshwater fauna of our island have been made. 

 Amongst the marine Copepoda there is one species {Euchceta 

 norvegica) which is often found in myriads in tow-net material 

 collected in the deeper waters of Loch Fyne. From a single 

 haul made with the mid-water net of the ' Garland ' in April 

 of this year sufficient Euchceta were obtained to more than fill 

 a large drop-jar, such as may be seen in confectioners' 

 windows, and yet its discovery is only of comparatively 

 recent date, no record of it appearing in Prof. Brady's 

 valuable monograph on the British Copepoda ; and this 

 species is certainly not a casual visitor. Further, Dr. John 

 Murray some years ago discovered in Loch Etive an Ostracod 

 [Conchcecia eJegans, G. 0. Sars) which had not been known 

 to exist within the British area, and this Ostracod can still 

 be obtained in abundance in the place where it was first 

 discovered, showing that it also is not a casual visitor. Other 

 examples could be given if necessary. 



The occurrence of so many additions to our crustacean 

 fauna is due, as has already been said, to the recent more or 

 less systematic prosecution of fishery investigations, and 

 probably also to greater care being taken in the discrimination 

 of species. The enjoyment of greater facilities for collecting 

 material and the adoption of improved methods in its exam- 

 ination have also doubtless tended to enlarge our knowledge 

 of the Crustacea, and especially of the more minute species ; 

 and it is to causes such as these, rather than to the iuduence 

 of the Gulf-stream or other currents, that the discovery of 

 most of the new and interesting species that have been 

 recently added to the Brirish fauna is to be ascribed. 



It is also noteworthy that many of the species of Copepoda 

 described within recent years by British students are being 

 found at continental stations and recognized by foreign autliors 

 as good species. 



EXPLANATION OF THE PLATES. 



Plate XVII. 



Fig. 1. Female, seen from the left side. X 100. 



Fig. 2. Antennule, female. X 95. 



Fig. 3. Antenna. X 127. 



Fig. 4. Maxilla, female. X 190. 



Fig. 5. Anterior foot-jaw. X 190. 



Fig. G. Posterior foot-ja\y. X 190. 



Fig. 7. Foot of tirst pair of swimming-feet. X 154. 



Fig. 8. Foot of second pair of swimming-feet. X 154. 



Fig. 9. Foot of fourth pair of swimming-feet. X 154. 



