"292 Proceedings of the Royal Irish Academy. 



note. Theridionjmlchelluni, common on the Azores and also on Madeira 

 and the Canary Islands, is likewise known from southern Europe, !Xorth 

 Airica, St. Helena, and South America. Segestria florenfAna occurs 

 in the Azores, the Canaiies, the Mediterranean region, and St. Helena ; 

 while Jjjjsdera crocata has a similar range, except that it has not yet 

 been discovered in the Canary Islands. 



The distribution of the minute white Pedipalp Kanenia raira- 

 hilis is most iustmctive. It lives uuder stones in southern Italy, 

 Sicily, and Tunis, and reappears again on the other side of the Atlantic, 

 in Chili and Texas. 



There is an exceedingly peculiar Phalangid, Cryptodemma^ 

 evidently an ancient type, of which only a single species is knowTi 

 to science — viz., 0. Weatermanni, which has been taken on the shores 

 ■of the Amazons in South America, and also on the banks of the Ejibi 

 liver in West Africa. 



Such instances need no comment. Uut it may be mentioned that, 

 from a study of the distribution of the Scoi-pions and theii- allies, llr. 

 Poeock has come to the conclusion (p. 230), which I have again and 

 agaiu suppoited in the preceding pages, that a Tertiary land- connection 

 must have existed between South America and Africa. 



The Acarids of Central America and those of Central Eui'ope appear 

 to be closely related, according to Professor Stoll. In some instances 

 even the same species are repi'esented in the two countries (p. 19). 



Centipedes and their allies. 



The Myriopod fauna of the Azores, described by Latzel, also very 

 closely resembles the Eui'opean ; and there is, as in other groups, a 

 distinct indigenous element. Professor Stoll draws attention to an 

 important case of distribution — viz., that of the genus Folyxenm, 

 which includes very minute and delicate Millipedes living in secluded 

 localities, and being characterised by a nocturnal hahitat and lack of 

 mobility. Three species are found in Europe and Xorth Africa ; while 

 others occur in Guatemala, the "V\'est Indies, and the southern States 

 of America. A single species has been discovered in Ceylon (p. 25). 



Crustaceans. 



The terrestrial Isopod Crustaceans, or " woodlice," are of much 

 value in zoogeographical research, as many of them pass theii* 

 existence entirely underground, and are therefore not liable to acci- 

 dental dispersal. Some others, frequenting the crevices or bark of 

 trees, may occasionally be swept into the sea on floating timber, and on 

 rare occasions be stranded on a foreign shore. A few woodlice, no 



