268 [May, 



which I have named similis, from the close resemblance which it bears 

 to 8. carnaria, differing from it only by the want of the dorsal spines 

 upon the edge of the second abdominal segment. In female specimens 

 of S. carnaria, these spines are sometimes small and absent ; and in 

 a few males I have found them much less than usual : it must there- 

 fore remain to be determined by future investigations whether S. 

 similis is to be ranked as a true species, or only a variety of S. carnaria. 



Bradford, Yorkshire : 



November, 1875. 



