Botany and Zoology. 423 



Islands, of which the only specimen in Europe was exhibited at the 

 meeting. The author supposes that the Dodo fed upon the cocoa-nuts, 

 mangos, and other fruits which in tropical forests fall from the trees at 

 all seasons of the year. The lecturer then drew attention to the island 

 of Rodriguez, visited in 1691 by Leguat; who has given a description 

 and figure of a brevipennate bird which he calls the Solitaire. Seve- 

 ral bones of this bird from the Museums of Paris and of Glasgow, were 

 on the table ; and a comparison of them with those of the Dodo clearly 

 proved that the "Solitaire" was an allied, but distinct species, — longer 

 legged than the Dodo, and related, like it, to the pigeons. It was next 

 shown, from the narratives of several voyagers, that the island of Bour- 

 bon was also formerly inhabited by two species of short-winged birds 

 of the same abnormal group as the Dodo and the Solitaire. Unfortu- 

 nately, we have as yet no osseous remains of these birds from Bour- 

 bon : — but they might doubtless be procured from the caves and alluvial 

 deposits of that island ; and by similar researches in Mauritius and Rod- 

 riguez, the entire skeletons of this remarkable family of extinct birds 

 might be reconstructed. 



4. Ekrenberg on the Sirocco-dust that fell at Genoa on the 16th 

 May, 1846, (Quart. Jour. Geol. Soc, No. 10, from the ■ Berlin Monats- 

 Bericht,' for 1846, p. 202-207.)— The microscopic analysis of this dust 

 produced 22 polygastrica, 21 phytolitharia, together with the pollen of 

 plants and the spores of Puccinium. The varieties of dust which since 

 1830 have fallen in the Atlantic Ocean, as far as 800 sea miles west 

 from Africa, on the Cape Verd islands, even in Malta and Genoa, 

 which the author has had an opportunity of examining, all agreed in 

 the following particulars : — 1st, they are all ochre yellow, never grey, 

 like the dust of the Khamseen in the north of Africa; 2nd, the color is 

 produced by iron oxyd ; 3rd, from one-sixth to one-third of their mass 

 consists of recognizable organic parts ; 4th, these are either siliceous 

 polygastrica and phytolitharia, or carbonaceous but uncarbonized portions 

 °f plants, or calcareous polythalamia ; 5th, the greater number of the 

 ninety species already found equally occur in the most widely separa- 

 ted of the places just named ; 6th, the most numerous forms are every 

 where land and freshwater productions ; yet some marine animalcules 

 are constantly mixed with them ; 7th, in no case were dried up, living 

 species (except the pollen and spores), nowhere melted, calcined, or 

 carbonized forms among them ; 8th, even the dust of Genoa, although 

 brought there by the Sirocco, exhibited as little as any of the former, 

 characteristic African forms, which yet are found in every small por- 

 tion of mud from Africa ; on the contrary, one of them, Synedra enlo- 

 m °n, is a decidedly characteristic South American form. It is remark- 

 able that the few (2?) European observations hitherto made have 

 always fallen on the 15th and 16th of May. The author concludes 

 with the question, whether there is not a current of air uniting Africa 

 and America in the region of the trade-winds, which is occasionally, 

 and especially on these days, turned towards Europe, and brings that 



dust along with it? , J' JJ" ^ 



5. A Fact respecting the Habits of Notonecta glauca ; by Prof. 

 Forrest Shepherd, (communicated for this Journal.)— In the evening 

 twilight of a pleasant day in September, 1846, Sir George Simpson en- 



