HABITS, 



HABITS. 



In their native haunts these animals exhibit considerable diversity of habit. The majority, 

 however, live under stones that lie on a muddy or sandy bottom, between tide-marks, either in 

 pools or moist places, and, as scarcely a vestige of them is at any time seen unless a stone is 

 upturned, their period of activity is probably during fall tide. As their haunts indicate, they are 

 fond of the shade, but I do not know that for this reason they are to be called, after De Quatre- 

 fages and others, nocturnal animals. Thus Lineus marinus is observed occasionally gliding 

 amongst the seaweeds of a warm and sunny tide-pool. 



Hundreds of some of the common forms, such as Lineus gesserensis and Cephalothrix linearis, 

 may be found under a single stone, sometimes in tangled masses, amidst the muddy sand so 

 common in such places. Tetrastemma dorsalis is gregarious, in vast flocks, on Ceramium and 

 other algse dredged in the Laminarian region ; and Prosorkockmus Claparedii is frequently found 

 in groups in fissures of the rocks near low-water mark in the Channel Islands. Leidy, in his 

 * Marine Invertebrata of Rhode Island and New Jersey/ also describes his Nemertes socialis as 

 very abundant, often in masses, about the roots of corallines, between tides, at Point Judith. 

 The larger and rarer forms occur either singly or in pairs, such as Nemertes Neesii and Micrura, 

 which haunt the fissures of rocks near low-water mark. The great Lineus marinus, again, is often 

 solitary, and the largest specimens almost always so, as well as limited in numbers — size, as in 

 some of the higher forms of marine life, being thus inimical to profusion ; and it may be noticed 

 that a diligent search for a lengthened period in one locality diminishes very sensibly the number 

 of large examples. Other Nemerteans frequent the coralline ground or its neighbourhood, 

 such as Micrura purpurea, Cerehratulus angidatus, Ampliiporus pidclier, and A. spectabilis, 

 and they are partial to empty bivalve shells. Stones placed near the verge of low water, and 

 covered with a profusion of algous and zoophytic life, furnish numerous specimens of the small 

 Tetrastemmce, which apparently delight to crawl amidst the roots and branches, no doubt 

 attracted by the abundance of the other animal organisms that like themselves seek shelter and 

 safety in these miniature forests. One of the best modes of collecting such small forms is to 

 chip off at the proper season — for their abundance is probably periodic — shelving fragments of 

 rock, and carry them home for immersion in shallow vessels of sea- water, when the worms leave 

 their retreats and crawl to the water-line of the basin, after the manner of Mssoce, Skenece, and 

 other small Mollusca. The same may be said of the roots of the tangles dragged from the rocks 

 near or beneath low-water mark, such treatment being often the only safe mode of procuring 

 perfect specimens of Carinella annidata, Nemertes Neesii, and N gracilis, which generally inter- 

 lace their lengthened bodies with the radicles. No richer ground for Nemerteans of rare size 

 and beauty probably exists than the intricate roots of the vast tangles that envelop the muddy 

 masses of horse-mussels in Bressay Sound, where Forbes and Jeffreys have each done such good 

 work by aid of the old drag of the Zetlandic fishermen. Colonies composed of examples of 

 different species, such as Lineus marinus, L. gesserensis, Micrura fasciolata, M. purpurea, 

 Nemertes Neesii, and AmpJdporus pulcher, are occasionally met with in the same root; while the 

 hollows of the rough roots of Laminaria bulbosa give shelter to select pairs or solitary individuals. 



