TEEEESTEIAL ISOI'ODA OF KEW ZKA l;.\ M). 101 



countries and places, for they are strictly terrestrial animals, and as their youny are 

 hatched in the incubatory pouch of the female, it seems unlikely that they could cross 

 even comparatively narrow tracts of ocean, exeejjt by rare accidents, while a continuous 

 range of high moimtains would also be a formidable liarrier. In the NeAV Zealand 

 Journal of Science, vol. ii. (1884) p. 155, I have already called attention to the question, 

 and have also jjointed out that their distribution in aoy given land-area may be to some 

 extent influenced by floods in the rivers carrying logs with the Isopods attached to great 

 distances, and have given the following instance where this a{)pears to have actually 

 taken place. 



The sjiecies Aruiadillo regulosus {=Cub(n-i.s i-egnlostis, Miers) is common on logs and 

 under the bark of trees in the bush, but I had not found it on the open Canterbury 

 Plains except at one place, Eyreton, where I got numerous specimens under some logs 

 that had been carted for firewood from the river Waimakariri, after having been washed 

 down by the river for at least twenty miles, probably furtlier, from places Avhere the 

 species was abundant. It seems likely that the Isopod had been washed down with the 

 logs, for I found it only at that particular spot at Eyreton, and af tei- the logs had all 

 been used it was no longer seen in that district. 



It would, therefore, be interesting if some facts could be given as to the distributiou 

 of our Xew Zealaud species, especially of any that may l)e found in other countries. 

 Unfortunately, however, so little is at present known of the Terrestrial Isopoda of 

 Aiistralia aiul other lands of the soiithern seas, that little can as yet be said Avith 

 certainty. 



Of the species, by far the greater part (18) are known only from New Zealand; two 

 species, Porcellio scaher, Latr. and Armadillidlmn vulgare, Latr., are cosmopolitan, aud 

 have probably been introduced by artificial means ; another species, Philoscia pubesceiis^ 

 Dana, appears to be identical with a species found at the Cape of Good Hope and at the 

 Seychelles ; Actcecia euehroa, Dana, is found in Tasmania as Avell as in New Zealand ; 

 while Lie/id norfc-zcalandia', Dana, and Onisciis piincf.atns, Thomson, are reioresentcd 

 in Tasmania l)y closely allied species, and Ti/los neozelaniaus is jn'obably equally closely 

 related to T. sjnnidosus, Dana, from Tierra del Fuego. In the genus Trlchoiilscus it is 

 rather difficult to make any comparison between the numerous species, but the genus 

 is a very widely distributed one, and species are known from Tristan d'Acunha and 

 Valparaiso *, and from the Straits of Magellan f . The genus Armadillo is represented 

 in New Zealand by at least six S2)ecies, the greater number of the species of the genus 

 occur in the tropical countries, and Budde-LundJ has pointed out that about half of 

 them are frotn the islands and shores of the Pacific. 



Of the distribution and occurrence of the diff'erent species in New Zealand itself a 

 little more can be said. Six species (i. e. lji[//a novce-zealandice, Tylos neozelaniciis, 

 Scypliax oruatiis, Actcecia euehroa, Actcecia opihensis, and Scyphoniscus waitatensis) are 



* DoUfus : " Isopodes terrestres du 'Challenger,"' Socii'ti- d'Etudes Sdentifiques de I'liris, xii'^ Aniiei; (ISDO), 

 p]). 5 & (separate oopj'). 



t Stebbing : Proc. Zool. Soc. London, 1900, Part iii. p. SfiG. 

 % Isopoda Tcrrestria, p. 16. 



16* 



