EVENINGS AT THE MICROSCOPE 



having apparently run together, so as to smooth and round 

 angles and fill up chinks, even where, as is often the case, 

 the globes themselves have only mutually approximated, 

 and not come into actual contact. 



The average dimensions of these oval aggregations may 

 be .004 inch in length, and a little more than .002 in 

 width ; but some specimens occur which are a little larger, 

 and others a little smaller than this; while the irregular 

 plates are sometimes three times the length. 



Some of the more worm- like members of this class 

 have, however, a skeleton composed of pieces imbedded 



in their skin, of even more re- 

 markable shapes than these. One 

 of these is the Chirodota violacea 

 a native of the southern coasts 

 of Europe. We have indeed a 

 British species of the same genus, 

 a specimen of which is in my pos- 

 session, but I have vainly exam- 

 ined the skin for any structure 

 analogous to this. 1 In the Medi- 

 terranean species the skin, especially of the belly-side, is 

 described as filled with plates exactly resembling broad 

 and thin wheels of glass, supported by four, five, or six 

 radiating spokes, and having the inner edge of the hoop 

 cut into teeth of excessive delicacy. 



Another animal remarkable for its cuticular furniture 

 is the genus Synapla, which is very similar in form, and 



1 The most careful and repeated search has not availed me to find in the 

 skin the least trace of calcareous atoms ; but this may possibly be because I had 

 unfortunately preserved my specimen in acetate of alumina and the acetic acid 

 has perhaps dissolved the lime. 



WHEEL IN CHIRODOTA.. 



