Abstract
The trematode and cestode parasites of fishes inhabiting British coastal waters have been the subject of several studies in the past, but the parasites of deep-sea fishes have received comparatively little attention due probably to the difficulty of obtaining fresh material. In order that such material might be obtained, excursions were made by the junior author in a commercial trawler to some of the deep-sea fishing grounds lying to the west of Ireland, namely, the Irish Atlantic Slope and the Porcupine Bank. Two excursions were made, the first in August 1938 and the second in July 1939, each extending over a period of about 12 days. In addition, a study has been made of the parasites of some fishes from the Irish Sea from 1936 to 1939. The results of both surveys are incorporated in this paper, and the areas investigated are indicated in Table 1.