04 Mr. C. J. With on Chelonetlu 



Diplovimatina {Gastropiychia) electa, sp. n. 



Shell sinistral, oblong-conic, greyish brown, moderately 

 solid, ornamented by fine and close-set oblique stride ; whorls 

 8, distinctly convex, regularly increasing ; aperture subovate, 

 orange within ; peristome double, the inner part exserted 

 forward and the outer expanded, orange-colour ; columella 

 tortuous, exjjanded at point of insertion, bearing a distinct 

 plait on the lower part, which is continued within the aper- 

 ture ; two interior plaits or callosities are seen from the 

 exterior, more plainly if the shell be wetted, the first appears 

 as a perpendicular orange-coloured line commencing just 

 above the point of insertion of columella and directed upwards, 

 the other runs near to and parallel with the suture, and is 

 situated just to tiie right of the aperture. 



Maj. diam. 3^; alt. 6^ mm. 



Hab. N. Borneo {Waterstradt) . 



This distinct species can easily be separated from D. ad- 

 versus, Ad., by its more regular form, stronger sculpture, and 

 more numerous whorls. 



X. — On Chelonethi, chiefly from the Australian Region, 

 in the Collection of the British Museum, with Observations 

 on the " Coxal Sac " and on some Cases of Abnormal 

 Segmentation, By C. J. With, Copenhagen. 



[Plates YI.-X.] 



The observations included in this paper were all made 

 on material belonging to the British jSIuseum (Natural 

 History). For the liberality with which the collections 

 of Chelonethi were handed over to me I tender to the 

 Director, Professor E. Bay Lankester, my best tlianks. 

 I am also grateful to Dr. W. T. Caiman, because he assisted 

 me with his extensive knowledge of literature, as well as 

 to several members of the entomological staff, especially 

 Col. Bingham, by whose kindness it became possible for me 

 to investigate some specimens of Hymenoptera which were 

 remarkable on account of their abnormal segmentation. 



In the following pages I have first given a revision of 

 the Australian species of Chelifer, because I had occasion to 

 examine a good many of the described species, and among 

 them several typical specimens. In addition to these, I have 



