70 Canon A. M. Norman on 



We thus have twelve Land Isopoda as known in Madeira. 

 Such a list must be far from complete ; and I trust that this 

 short notice may lead others to investigate this portion of the 

 Madeiran fauna. The Madeiran group is rich to a most 

 remarkable degree in Land Mollusca, and it may prove to be 

 so in Land Isopoda. With the exception of Lucasius Nor- 

 rnani all the species I myself met with were collected close 

 to Funchal. The whole of the rest of Madeira remains to 

 be explored, and I am not aware that any carcinologist has 

 even so much as set foot upon the islands of the Desertas and 

 Porto Santo, which are so rich in Mollusca peculiar to them. 



There are two remarkable features with respect to the Land 

 Mollusca of the Madeiran Islands — first, that, as a rule, each 

 form has a peculiarly restricted range in the islands, and, 

 secondly, that out of 176 species, as recorded by Wollaston, 

 only 25 occur in Europe. 



The first of these features may be found to be paralleled 

 hereafter among the Isopoda; but as regards the second, out 

 of the twelve Isopoda in the preceding list, seven are Euro- 

 pean and only five are not so. However, it must be remem- 

 bered that the species hitherto found have been mostly met 

 with in the immediate neighbourhood of the seaport and from 

 the most likely part of the island to contain introduced 

 species. Of the five which are not European, Armadillo- 

 niscus tuberculatus inhabits the Azores, while ArmadilUdium 

 tigris, Porcellio maculipes, Lucasius scitus, and Lucasius 

 Normani are, as far as is yet known, 'peculiar to Madeira. 



The Land Isopoda have been more sought for in the Azores 

 and Canaries than in Madeira, and thus from the former 

 group of islands twenty species are known and from the 

 latter nineteen. 



EXPLANATION OF PLATE VI. Figs. 1-4. 



Fig. 1. Lucasius Normani, A. Dollfus, sp. n. Head and first segment of 



perseon. 

 Fig. 2. Ditto. Head seen from below. 



Fig, 3. Ditto. Fifth segment of pleon, pleotelson, and uropods. 

 Fig. 4. Ditto. First pleopod of the male. 



IX. — British Land Isopoda. 

 By Canon A. M. Norman, M.A., D.C.L , LL.D., F.R.S., &c. 



[Plate VI. figs. 5-12.] 



Since the publication of Bate and Westwood's ' History of 

 British Sessile-eyed Crustacea,' 1869 *, the following papers 

 * Dated 1868, but the last part, which included the Land Isopoda, 

 was not published until 1869. 



