252 MECZNIKOW, ON ICHTHYDIUM, ETC. 
second, fourth, sixth, tenth, twelfth, fourteenth, and seven- 
teenth segments, on the ventral surface, and in all the rest 
on the dorsal surface (compare Pl. V, fig. 9). The side 
bristles are placed on the left of those segments which carry 
the ventral median bristles, and in the rest on the right. The 
last, and at the same time the smallest, ring forms an excep- 
tion, in that its two terminal bristles are very near one another, 
‘and arise from the under edge of the segment. 
These remarks may be sufficient to show, in spite of the 
contrary supposition of Claperéde, that these animals are not 
in any way allied to the Annelids, and in fact not to the 
Worms at all. It strikes me as being probable that Desmos- 
colex is the larval condition of a known or unknown Arthropod, 
and I can only hope that more fortunate researches may very 
soon give a firmer footing for a judgment on the question. 
