FROM THE EDDYSTONE GROUNDS TO START POINT. 397 



are comparatively scarce, only twenty individuals were found in 0'45 

 grams (seven grains), or 4-4 per gram. In 91 YII. sixty-seven fora- 

 minifera were counted in O'lo gram (two grains), or 515 per gram. 

 In VI. Rotalia heccarii was present to the almost total exclusion of 

 every other form, while in YII. the individuals of this species 

 practically equalled in number those of all other species added 

 together. Arranged in order of frequency the following is the list of 

 species : — Rotalia heccarii, Miliolina seminulum, Textularia gramen, 

 Truncatulina lohakda, Discorbina rosacea, Boliviiia dilatata, Plan- 

 orhulina mediterrancnsis. In all, seven species. — E, H. W.] 



There are very few shells on this ground. 



Burroiving sjjccies. As on the inner trawling ground (I.), Astropecten 

 irregularis and Dentaliuvi entalis are abundant. Corystcs cassivelaunus, 

 which on the inner trawling ground was taken in haul 92 only, is here 

 abundant in all hauls excepting 53 and 56. From the position of the 

 various hauls it will therefore be seen that a centre of distribution of 

 this species occurs on the S.E. portion of Ground III. and the N.W. 

 of Ground I. (Chart XIII., cf. also p. 492.) There is no evidence of 

 Cardium echinatum on the present ground. Aphrodite aculeata is 

 occasionally taken. 



Fixed species. The most obvious distinction between the ground now 

 under consideration and the inner trawling ground (1.), which adjoins 

 it, is the much greater abundance of Cellaria and the much richer 

 hydroid fauna. Of the hydroids which fix themselves in the sand 

 by a felt-work of root-fibres Aglaophenia myriophyllmn is invariably 

 taken, and is much commoner than on Ground I., and Antennularia 

 antennina is common also. 



SertulareUa Gayi is very common, being by far the most plentiful 



hydroid on the ground, and is generally attached to the tube of Thelepus. 



It is associated, as on the inner trawling ground, with Sahella (pavoninal) 



and Ascidiella scahra. The other characteristic hydroids are SertulareUa 



polyzonias, Eiidendrium ramosum, Bougainvillia ramosa, Plumularia 



pinnata, Plumularia Catharina, and occasional specimens of Hydrall- 



mania falcata. Lafoea dumosa, var. rohusta, is not uncommon, associated 



with Coppinia arcta and Dondersia banyulensis. Occasional specimens 



of Halecium halecinum and Halecium Bcanii are the result of the 



influence of the neighbouring Eddystone gravel grounds, which is 



also shown by one or two specimens of Chactopterns. Ahyoimim 



digitatum occurs only as small colonies, and one specimen of Paraphellia 



expansa was taken in haul 72. Cellaria fistiilosa and Cellaria simtosa 



are both abundant, and Bicellaria ciliata, Cellepora avicularis, Ccllepora 



raviulosa, Scrupocellaria scraposa are common on hydroids, but incrust- 



ing Polyzoa are very scarce. 



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NEW .SERIES.— VOL. V. NO. 4. - ^' 



