368 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



eosin and appears pinkish in colour (figs. 16 and 17). 

 Interspersed among the tubercles are numerous hairs, some 

 of which are small and pilose, while others are larger and 

 stouter and rather of the nature of setae. The latter kind 

 are specially prominent about the sides of the head and 

 on the lateral margins of the abdominal segments (figs. 

 1 and 3). Both kinds of hairs arise from a circular base 

 (fig. 6), which, when viewed in section, is seen to be in 

 reality a cup-like depression in the cuticle (fig. 17). 



The hypodermis, or chitogenous layer, is everywhere 

 of the nature of a syncytium, no cell boundaries being 

 distinguishable. Its cellular nature is evident, however, 

 by the presence of numerous large oval nuclei. It contains 

 a great quantity of a very dark indigo-blue pigment 

 (p. in fig. 16), and it is to this material that the 

 colouration of the animal is due. The pigment is 

 deposited in the form of minute granules and, except in 

 very thin sections, it appears black, and frequently 

 greatly obscures the nuclei. On the ventral aspect of the 

 body, which is less exposed to the influence of light, the 

 pigment is not quite so abundant as in other parts. When 

 a number of freshly-caught examples of Anurida are 

 placed in a small quantity of strong alcohol a little 

 of the pigment becomes soluble in the latter and imparts 

 to it a faint bluish-green tinge. The bulk of the 

 pigment, however, appears to be incapable of being 

 extracted by most of the ordinary reagents. It is not 

 dissolved out by water, neither does ether nor strong 

 hydrochloric acid affect it, and Fernald (8) remarks that 

 when sections of the animal were treated with 45 per cent, 

 nitric acid for ten minutes the latter failed to remove the 

 pigment. "Weak solutions of strong alkalies turn it a 

 bright reddish colour. Distributed at intervals in the 

 hypodermis are large, pear-shaped cells (h. cell, in fig. 17), 



