4G0 dr. f. b. white on the [May 7, 



For example, there is the one peculiar land-bird, Aigialites 

 sanctcB-helencB, which is so closely allied to xlfrican species that it 

 is, in all probability, a comparatively recent introduction. It seems 

 rather remarkable that there are not more peculiar land-birds ; and 

 the absence of Bats (none of which are recorded by Mr. Melliss) is 

 another curious feature in the fauna of the island. 



There are also the species of West-Indian fish and marine Mol- 

 lusca as well as the Indian-Ocean species of the same groups. Not 

 very much can be made out of our present knowledge of these ; but 

 it seems to me that no great obstacle exists to their introduction by 

 means of the ocean currents. The present currents might have 

 brought the southern and eastern species, while the reversal of the 

 currents during a glacial period would bring the West-Indian and 

 Brazilian animals. Though I have already invoked the agency of a 

 reversed current for the purpose of bringing the Palsearctic fauna 

 to the island, I think it is improbable that the arrival of the West- 

 Indian fish at St. Helena was contemporaneous with that of the 

 ancestors of the endemic fauna, though, in the case of some of them, 

 it is quite possible. I would rather suppose that, since they are 

 species of presumably later origin (or, should their origin be as 

 remote as that of the endemic species, yet it was elsewhere than at 

 St. Helena), they were brought to the island during a later (or a 

 later part of the last) glacial period than the ancestors of the endemic 

 species. 



There are also certain elements in the flora, viz. the five tropical 

 weeds or sea-side plants of very wide distribution, which Sir. J. 

 Hooker refers to. These are almost certainly of later introduction 

 than the endemic and peculiar flora. Mr. Melliss remarks \ of 

 Entadu scandens, L., that the large seeds ** are cast ashore on the 

 windward side of the island, having been brought from the Mau- 

 ritius, or elsewhere, by sea-currents. They have been known to 

 germinate ; but it is doubtful if one now exists there." This fact 

 is suggestive of the origin of the five plants alluded to, as well as of 

 some others thought by Mr. Melliss to be indigenous. 



Part II. Descriptive. 



In his recent work upon St. Helena, Mr. Melliss was able to 

 record the occurrence of only 8 species of Hemiptera. The names 

 of only five species had apparently been determined ; and of these 4 

 were evident introductions. 



It was therefore left to Mr. Wollaston to add considerably to our 

 knowledge of the St.-Helenian species of this order. The list which 

 I now submit to the Society embraces the results of his six months' 

 exploration of the island ; and though it probably does not include 

 all the native species, yet there is reason to suppose that the collection 

 is a very representative one. 



A few months before his lamented death, Mr. Wollaston placed 

 the collection in my hands for determination, with directions that a 



1 L. c. p. 266. 



