r 37 1 >''vi!«ii««"i8n«?^^ 



IV. 



THE HOLOTHUEIOIDEA OF THE COASTS OF lEELAND. 

 By AKNE L. massy. 



Eead December 16, 1919. Published Apkil 8, 1920. 



About 25 species of this group are distributed round our shores and 

 in the deep water off the west coast, and further research in the latter 

 region will probably add to the number. Among the specimens taken by 

 the naturalists of the Fisheries Branch of the Department of Agriculture and 

 Technical Instruction for Ireland since the publication of Mr. Kemp's paper' 

 the following are additions to the British and Irish area : — Stichoims regalis 

 (Cuvier), Mesothuria Vernlli (Theel), and Benthogone rosea, Koehler. Four 

 other species, Batliyplotes Tizardi (Theel), Ulesothima ladea (Theel), 

 Cucumaria Normani, Pace, and Pseudociccumis mixta, Ostergren, possess 

 names new to the Irish fauna ; but I believe they have been already found 

 off our west coast, but were recorded under other names. Mesothuria lactea, 

 Mesothuria Verrilli, and Benthogone rosea appear to be species of the warmer 

 parts of the Atlantic, and probably reach their northern limit at about 52° 

 N. latitude. Stichopus regalis occurs in the Mediterranean, and is known as 

 far south as the Canaries, but has not tmtil now been observed north of the 

 Bay of Biscay, it has been recorded from Australia with a query by Semper; 

 but as it is not a very deep water species, it would seem to be more likely 

 that the Australian record refers to the nearly allied Stiehoinis nigri- 

 punctatus, Augustin, a Japanese species. Bathyplotes Tizardi is a deep water 

 species, with a range extending in the Atlantic from 60° N., lat. to 

 Senegal. It has also been recorded from Japan, and probably future 

 investigation will show that, like Laetmogone violacea, Theel, it is an oceanic 

 species of very wide distribution. Pseudocucumis mixta is known from 

 western Europe, and seems to have been frequently confounded with 

 Phylloplourus /lellucidus and other species. Ostergren, with regard to this 

 confusion, has pointed out the importance of studying the calcareous collar 

 in Holothurians, as species haviug much the same outward appearance, 

 and apparently identical deposits, may possess collars of a totally different 

 structure. The only British species which have not been observed on our 

 coasts appear to be Cucumaria frondosa (Gunnerus) and Labidoplax Biiski 



' "Ann. Rep. Fish. Irel.," 1902-03, pt. ii, App. vi (1905). 



SCIENT. PROC. K.D.S., VOL. XVI., NO. IV. I' 



