LOXOSOMA LOXAMNA AND LOXOSOMA SALTANS. 127 
possible that a somewhat different thougli less lively mode 
of progression may be possessed by L. Daveuporti from 
what Nickerson says, though there is no modification, nor 
similar action, of the four oral tentacles. Nor is the oral 
part of the lophophore rim indented. In L. Davenporti 
there are certain cells at the base of each tentacle on its 
outer surface, “ the cuticula over the cell” being “ thickened 
to form a flattened or sucker-like protuberance.” Nickerson 
continues (p. 355): “If a number of specimens in clear 
sea-water in a smooth glass vessel be observed attentively, 
individuals may often be seen lying on the dorsal surface 
with the lophophore fully expanded. If a current of water 
from a pipette be directed against an animal in this position 
it becomes evident at once that the creature is attached 
quite firmly by the lophophore margin ; and though the 
foot end may be lifted up by the motion of the water, the 
hold of the animal is loosened only by a very strong current. 
This observation makes it evident that the cells in question 
serve as a means of attachment. They are to be regarded as 
unicellular suckers, which are of use to the animal in 
enabling it to keep a hold upon its host while changing its 
foot attachment.” 
External F orm. — The livinganimal is almost transparent 
and colourless except for the excretory organs and alimentary 
canal, which is throughout slightly yellow, and at certain 
points it is strongly pigmented and shows up brightly. The 
pigmented portions are the two distal and lateral swellings 
on the stomach, which vary from a bright yellow or orange 
to brown (fig. 19), and the latter part of the alimentary canal 
oi- rectum which is wider than the intestine. The two 
smaller and proximal diverticuja of the alimentary canal, 
which in sections are seen to take stain more readily than 
any other part of the alimentary canal, are almost quite 
devoid of any colour in the living animal. Fig. 19 illustrates 
the colour of the living animal and fig. 10 the general form 
and character. In this specimen there were two large pedun- 
culate “ flask organs,” of which one is shown in fig. 10, 
