4 Prof. W. C. i^l'Intosh on certain 



The second group is formed bj tliose which inhabit sand, — 

 some, like Neplithya^ forcing their agile muscular bodies 

 through the moist sand in serpentine waves, almost without 

 an eflfort, while the more stationary lob-worm of the beach 

 mimics the habitat of the familiar earthworm. Under this 

 head are Ghjcera^ Annitis rosea^ Phyllodoce maculata, 

 Ophelia, Ammotrypane^ Aricia, ScoloploSy Nerine, and Scole- 

 colepis. 



Those of the third series frequent chinks or other spaces in 

 the rocks, such as Nereis pelagica, Lumhriconereis, Leodice, 

 and ]\Iarpliysa ; while the fourth series comprises those 

 dwelling in peat, for example Uediste diversicolor and Stra- 

 tonice Marionii. The dwellers in hollow tangles, such as 

 Leontis Dumerilii^ form a fifth group. 



A large number, again, secrete from the surface-glands of 

 their bodies a fluid which hardens in seawater, and with 

 which they build up for themselves houses of greater or less 

 complexity, using it as mortar for fixing sand-grains, gravel, 

 fragments of shells, and similar structures. Under this, the 

 sixth group, fall Xorthia, Chcctopteriis, Spio, Polydora (in 

 part), Sahellaria.j Oicenia, Lagis, Ampkictetie, CistenideSj 

 AmjyJiarete, Ampliicteis^ Amphitrite^ Terehella^ Lanice, 

 Axionice, TheJepus^ Grymcea^ and others. 



The seventh group includes those which add no foreign 

 element to the translucent tubes which they secrete ; such 

 tubes being soft and gelatinous, as in Myxicola, flexible, as 

 in Spioc/ia'tojjieriiSj or so firm and tough as to be fashioned 

 into pens for writing, as in Ilyalincecia. 



In a subsection of this assemblage may be placed some 

 Avhich attach their translucent tubes to blades of tangle or 

 other seaweeds, like EusyUis ; or which have dense leathery 

 tubes amongst sponges and zoophytes, as in certain species of 

 Eunice. 



]\Iany living in mud at the bottom of the sea fashion their 

 tubular dwellings chiefly of this deposit — either pure, or more 

 or less mixed with sand and fragments of shells, the interior 

 being lined with a smooth layer of secretion, which, in 

 Sabella, is often so abundant as to make the tubes extremely 

 tough. Under this (the eighth) head are such as Maldane^ 

 Axiothea, Pisia, DasychonCj Chone. 



The forms which secrete hard calcareous or porcellaneous 

 tubes constitute the ninth series — so widely and conspicuously 

 distributed on the soa-bed from low-water mark to the 

 greatest de])th yet exomincd, and though generally fixed are 

 sometimes I'rce. Protnla^ Filigrana, Nydroides, Poniato- 

 cerasj Placosteyus, Ditrypa, and Sj)irorbis are examples. 



