532 FLORENCE BUCHANAN. 



In the spirit collections of the British Museum there are 

 fifty specimens belonging to the genus Araphinome well enough 

 preserved for one to be certain whether or not the segmenta- 

 tion is regular and bilaterally symmetrical. Of these, twenty- 

 seven present variations in symmetry of one kind or another. It 

 is the presence of another species of Amphinome (A, [s. str.] 

 rostrata. Pall.), of which there are no specimens in the other 

 two collections, which raises the proportion so greatly. Of 

 this species there are seventeen specimens, of which only one is 

 regularly segmented throughout. The other sixteen all have 

 their segmentation irregular towards the posterior extremity 

 of the body, and the irregularity may take the form either 

 of a spiral or of intercalation of half-segments, but more 

 frequently a condition obtains which would seem to be inter- 

 mediate between regular and spiral segmentation, — that is to 

 say, the furrows which separate the segments form short spirals 

 instead of circles; but, as they are not continuous with one 

 another, the segments themselves do not take the form of a 

 spiral. The arrangement will be best understood by a glance 

 at fig. 4, where I have represented five successive segments 

 whose intervening furrows do not meet on the dorsal surface. 

 Sometimes it is on the ventral surface that they do not meet, 

 and sometimes they do not meet on either in which case the 

 furrows form a number of half-rounds of spirals. Very 

 frequently there are one or more complete segments in the 

 midst of a succession of incomplete ones. These and other 

 details are shown in the following table : 



