526 EEPOBT— 1893. 



The Marine Zoology of the Irish Sea. — Report of the Committee, 

 consisting of Mr. George Brook, Professor A. C. Haddon, 

 Mr. W. E. HoYLE, Mr. I. C. Thompson {Secretary), Mr. A. 0. 

 Walker, and Professor W. A. Herdman {Chairman). 



[PLATE IV.] 



Circumstances have prevented Mr. Brook,' Professor Haddon, and 

 Mr. Hoyle from taking much practical part in the work ; but the other 

 three members of the Committee have all been present on nearly all the 

 expeditions, and they have received much assistance from their colleagues 

 of the Liverpool Marine Biology Committee and from some of the other 

 naturalists who have been working at the Port Erin Biological Station 

 during this year. The present report is drawn up by the Chairman, 

 with contributions from Mr. Thompson and Mr. Walker, and from other 

 naturalists, in regard to the groups of animals they have severally under- 

 taken to investigate. 



The area which this Committee was appointed to explore is that 

 region of the Irish Sea which lies around the Isle of Man (see chart, 

 Plate IV.), and which is classic ground to the marine biologist as being the 

 scene of the first pioneer work of Professor Edward Forbes more than 

 sixty years ago. Some few parts of the area were also investigated more 

 minutely later on by Forbes in conjunction with Mr. R. McAndrew, a 

 Li-\'-erpool merchant well known in science from the extensive dredging 

 operations he conducted from his yacht along the north-west coasts of 

 Europe from the Mediterranean to the north of Norway. The greater 

 part of our area, however, has never been thoroughly explored, and some 

 parts are still unknown ground to the naturalist. It is an interesting 

 region from the considerable diversity of shore, of depth, and of bottom 

 which it presents, and, as your Committee hope to show, it possesses an 

 abundant fauna, including a number of rare and novel forms. 



A continuation of the deep-water depression runs down from the 

 Clyde sea area on the western side of the Isle of Man (see chart and 

 section, Plate IV.), and gives depths of 70 to 80 fathoms within 12 

 miles of land. The bottom of this depression is occupied by a stiff 

 blue-grey clay-mud, in which we find the annelids Panthalis Oerstedi 

 and Lipobranchius Jeffreysii, the crustacean Calocaris Macanclrece, the 

 echinoderms Bnssopsis lyrifera and AmpMura Chiajii, the pennatulid 

 Virgularia mirahilis, and the mollusc Isocardia cor. 



In moderate depths on the sides of the depression we come upon 

 varied bottoms of sand and sandy mud, gravel, dead shells, &c., on 

 which is a rich fauna representing all the usual invertebrate groups. It 

 is from this region that the greater number of our additions to the 

 British fauna have come. On April 30, from a depth of 46 fathoms, 

 we obtained two specimens of Cydostrema millepuiidatum, Friele, a 

 species only previously known from a depth of 649 fathoms near the 

 Lofoten Islands in the north of Norway. From depths of 25 to 30 

 fathoms, to the west of Port Erin, we have obtained in considerable 

 quantity the interesting ascidian Forhesella tessellata, which unites, in a 



' The sudden death of our friend and coileague Mr. George Brook has occurred 

 since this report was drawn up. 



