ANNELIDA. 
105 
The Nemerteans, again, are especially abundant between 
tide-marks, though some range thence to deep water, and a 
few occur only in the latter. Amphiporus lactijloreus is 
common under stones, and Linens gesserensis and Gephalothrix 
linearis in still greater numbers, especially in muddy places. 
The great Linens marinus is frequently found under stones, and 
occasionally in the pools. Near low water the Tetrastemmce 
(such as T. melanocephala , T. Candida , T. vermicula , T.jlavida, 
and occasionally T. dorsalis ) occur in varying numbers, the 
latter, however, attaining its maximum amongst the red sea¬ 
weeds in the laminarian region. By splitting the rocks at 
fissures Nemertes Neesii, Linens bilineatus, Micrura fasciolata, 
M. purpurea , and Carinella annulata are found in great beauty ; 
while the intricacies in the roots of the tangles afford favourite 
sites for Nemertes gracilis and others already mentioned. The 
debris in the fishing-boats is especially productive of fine 
examples of Amphiporus pulcher and Micrura fnsca *, both, 
besides the ordinary method of progression, swimming grace¬ 
fully through the w'ater like freshwater leeches, by throwing 
themselves on edge and striking right and left alternately 
with their flattened tails. The curious Nemertes carcinophila 
is abundant on the ovigerous abdominal hairs of the females of 
the shore-crab. 
Almost all the Nemerteans live well in confinement; and 
while the development of several is known, that of others 
(such as Nemertes Neesii 7 N. gracilis , Lineus marinus , L. 
sanguineus , the Micrurce , and Carinella annulata) affords a 
fine field for further research. The Nemerteans approach the 
Annelids proper very closely. 
The Rhabdoccela are generally minute, but tolerably numer¬ 
ous amongst the red ascidians hanging from cavern-roofs, or 
algous and zoophytic growths on the under surface of stones, 
in tidal pools and near low-water mark. 
The Planarians are fairly represented, the common forms 
frequently occurring under stones between tide-marks, and 
* A fine specimen of tlie large Cerebratuius cmgulatus, 0. F. Miiller, 
was sent me from the neighbouring Bay of Montrose by Dr. Howden ; 
but unfortunately no proboscis was present. The two forms closely ap¬ 
proach each other. 
P 
