ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 469 



c. General- 

 Marine Ecology.* — R. Southern discusses the various communities 

 of animals on the floor of the sea in the Clare Island area. Numerous 

 habitats are distinguished : sub-terrestrial mud, with small Nematodes 

 and Oligochrets, and such molluscs as Paludestrina stagnalis and Phytia 

 myosotis ; brackish estuarine mud, with Nereis diversicolor, etc. ; 

 estuarine mud, with Zostera, with. Ammonia sulcata, Esperiopsis fucorum, 

 Gibbula cineraria, and species of Rissoa attached to the leaves, with 

 many Crustaceans and the pipe-fish swimming about, with a rich fauna 

 among the roots, including numerous Polychsets, such as Macroclneta 

 clavicornis and Polyopkthalmus pictus • estuarine mud, with Litho- 

 thamnion, with the characteristic Gibbula magus, and such forms as 

 Scoloplos armiger, Porcellana longicornis, Acmsea virginea, and Bittium 

 reticulatum ; estuarine mud, without Zostera or Lithothamnion, with 

 Amphuira chiajii, Ophiothrix fragilis, Nephthys Itombergi, Aricia cuvieri, 

 Terebellides strmmii, Notomastus latericeus, Phascolosoma procerum, and 

 Acera Indlata as characteristic species ; coastal mud (not represented in 

 the area) ; abyssal mud or ooze (beginning to appear at 300 to 400 

 fathoms) ; sub-terrestrial sand, with few animals save the sand-hoppers 

 Talitrus saltator and Orchestia gammarellus, " which often occur in vast 

 numbers, so that the noise of their bodies falling on the sand is like 

 that made by a heavy shower of rain " ; sand, with Zostera, with Nereis 

 n/ltrifera, Scoloplos armiger, Cirratulus tentaculatus, and many other 

 Polychaets, as also Synapta inhserens ; littoral clean sand, without 

 Zostera, with species that burrow deeply into the sand, such as Arenicola 

 marina ; sub-littoral (sheltered) sand, without Zostera and with few 

 shells, with Ficulina ficus, Antennularia antennina, Antedon bifida, 

 Aphrodite aculeata, etc., as characteristic species ; sub-littoral clean 

 sand, without Zostera, with many shells, with Metridium dianthus, 

 Ophiocoma nigra, Pandalus montagui, Chitons, Nudibranchs, and 

 Lepadogaster bimaculatus ; coastal green sand, with a large fauna : 

 muddy estuarine gravel, with Zostera, with a mixed association ; muddy 

 estuarine gravel, with Lithothamnion, with a mixed association ; 

 muddy estuarine gravel, without Zostera or Lithothamnion, with a rich 

 fauna ; coastal sandy gravel, with large number of Polygordius lacteus 

 and Pectunculus glycimeris ; coastal shelly gravel ; coastal gravel, with 

 Lithothamnion ; the sub-terrestrial rocky zone, with insects, mites, 

 acorn-shells, periwinkles, etc. ; the rocky brackish-water seaweed zone, 

 with animals exposed on rocks, hidden under stones, in crevices, etc. ; 

 the Laminaria zone, with Helcion pellucida, etc. ; the zone of red sea- 

 weeds ; the coastal rough ground ; and the abyssal rough ground (not 

 represented in the area). 



The author takes a survey of the associations of animals found in 

 the littoral and sub-littoral areas. The chief characteristics of the 

 littoral fauna of Clare Island are the presence of species that thrive in 

 exposed conditions, or require water of a high degree of purity and 

 salinity, with equable conditions of temperature ; and, on the other 



* Proc. R. Irish Acad., xxxi. (1915) Clare Island Survey, pt. 67, pp. 1-110 

 (2 maps). 



