and Classification of the Opilionea. 513 



b. Sternum not narrow and compressed be- 

 tween the coxfe of the fifth appenda^e3, 

 wider at this point than in front, either 

 narrowly triangular and gradually ex- 

 panding from before backwards be- 

 tween the coxfe of the fifth appendages 

 or narrowly pentagonal and somewhat 

 abruptly expanding between them ; 

 stigmata concealed Fani. Ad^id.e, nov. 



The Insidiatores are confined to the southern portion of the 

 Great Continents. The Tritenonychidas contain the genera 

 ^4cM?no/i^?'a from ]\Iadagascar; Diasia from Chili ; Trifcnony.v 

 from Chili^ New Zeahand^ Australia, and Fiji ; Nuncia, whicli 

 is hardly separable generically from TruBnonyon, from New 

 Zealand ; and two new genera to be shortly described, one 

 from New Zealand, the other from Tasmania. 



The characters of the Trisnobunidce are taken from a 

 specimen belonging to a Tasmanian species in the British 

 Museum which I refer to Tricenohunus. The type of the 

 latter was from Queensland. 



The Ada^idffi are represented by two genera. Adceum^ of 

 which the British Museum has examples, is confined to 

 S. Africa and New Zealand. 



The genus Larifuga^ to which belongs P. I'ugosum, Guer., 

 of which the type is in the British 

 S. African. 



Part III.— Further Notes on the Sterna and on the 

 Segmentation of the Abdomen. 



In the paper already quoted Borner states that, on account 

 of the forward projection of the genital plate between the 

 coxEe of the appendages of the sixth pair in Leptopsalis and 

 Pachylus and the encroachment of the coxffi of the fourth and 

 fifth pairs towards the middle line in the members of tlie 

 group — the Mecostethi — to which Pachylus belongs, the 

 sternites of the fourth, fifth, and sixth somites of the prosoma 

 are mostly wanting in these groups, although in Leptopsalis 

 amongst the Anepignathi or Cyj)hophthalmi that of the fifth 

 persists ; and in the table, also cited above, the sterna of the 

 fourth and fifth somites are indicated as absent in Pachylus 

 and that of the sixth as replaced by tlie genital plate. 



It is difficult to reconcile this opinion with the known facts. 

 In the Mecostethi (including Pachylus) the sternal plates of 

 the fourth, fifth, and sixth somites of the prosoma are repre- 

 sented by a firmly chitinized, narrow, unsegmented, longitu- 

 dinal plate lying between the coxaj of the fourth and fifth 



