REPORTS 



ON 



THE STATE OF SCIENCE. 



Report on Dredging among the Channel Isles. 

 By J. Gwyn Jeffreys, F.R.S. 



Our dredgings, which occupied six weeks, were confined to the coasts of 

 Guernsey and Jersey. Owing to the rocky nature of the sea- hed, and to the 

 extraordinary rapidity of the tides, the work was very difficult and unsatis- 

 factory ; and one of my dredges was unavoidably lost, notwithstanding the 

 rope was a new one and every precaution had been taken to prevent an 

 accident of this kind. The depth of water seldom exceeded 30 fathoms ; 

 although there was one remarkable exception in a long submarine trough, 

 called Hurd's Deep, lying about fifteen miles north of Guernsey, and having 

 a depth of 60 fathoms and more. 



As regards the Mollusca (to which I shall, as in former Beports, confine 

 myself), they exhibit somewhat of a Mediterranean or South-European cha- 

 racter. This will appear from the accompanying lists. No new species were 

 procured; but scientific research does not consist entirely of such discoveries. 

 It may be well questioned whether the reduction of some forms, which have 

 heretofore been regarded as species, to the rank of varieties may not be of 

 equal importance. The sexual relation of known species, their development, 

 mode of growth, food, habits, economy, geographical and bathymetrical dis- 

 tribution, are all matters which require careful investigation. I had likewise 

 an opportunity of observing for the first time the animals or soft parts of 

 several species of shell-bearing Mollusca, and of rectifying the published 

 descriptions of other species. In the first of these categories I would 

 enumerate Cardium papillosum, Rissoa crenulata, R. striatula, Defrancia 

 Philberti, and Mangelia laevigata. In the second category may be placed 

 Qaleomma Turtoni, Chiton discrepans, C. cancellatus, and Trochus exasperatus. 

 Among the rarer or more local species taken by us were Argiope capsula, 

 Cardium papillosum, Tellina balaustina, and Crimora papillata. It was also 

 noteworthy that Aplysia depilans and A. punctata (usually considered distinct 

 species) copulated when a pair was placed in a vessel of sea-water. This 

 genus is not hermaphrodite in the same sense as Helix, inasmuch as each 



1865, B 



