Botany and Zoology. 77 



introduction to fifty years of botanical activity. The examina- 

 tion* of neglected and difficult groups of plants possessed a peculiar 

 charm for this morphologist. Thoroughly grounded in the prin- 

 ciples of morphology, he was able to make all of his work of the 

 highest order. It was fitting that these valuable contributions 

 should be brought together into a memorial volume. That this 

 volume has been made entirely worthy of him whom it commem- 

 orates is due primarily to the affectionate appreciation of Dr. 

 Engelmann's friend and neighbor, Mr. Henry Shaw, who has 

 taken pride in lavishing expense upon this superb record of criti- 

 cal investigation. It is another proof, if indeed any were needed, 

 of the sincere interest in scientific botany which is felt by the 

 munificent founder of the Shaw School of Botany. To the edi- 

 tors belongs the credit of judiciously preparing the text for 

 jmblication, by most careful collation. Since it is a memorial 

 volume it has been left without editorial comment even at those 

 points where comment might under other circumstances have been 

 desirable. 



3. Excursions Zoologiques clans les Isles cle Fayal et de San 

 Miguel (Acores), par Jules de Gueexe. Campagnes Scien- 

 tifiques du Yacht Monegasque L'Hieondelle. Troisieme annee, 

 1887. — The voyages of the Hirondelle are under the direction of 

 S. A. le Prince Albert de Monaco, with the " collaboration " of 

 Professor S. Pouchet, and have in view the study of the currents, 

 life, etc., of the ocean. A stay .at the Azores for some time in 

 1887 enabled M. J. de Guerne to study the life of some fresh- 

 water lakes of San Miguel and Fayal. The lakes of San Miguel 

 are situated in the crater of Sete Cidades at the west end of the 

 island. The crater is nearly circular, and has a longer diameter 

 (W.N.W.-E.S.E.) of 5 kilometers, and the highest point around 

 it is 846 meters above the sea. There are four lakes at the 

 bottom, 3 kilometers square and less in size ; three of them about 

 270 meters above sea-level and 22 to 30 meters in maximum 

 depth. Two of them, Lagoa Grande and L. Azul, probably date 

 from the year 1444, and a third from 1563. The Fayal lake 

 cannot date back of the eruption of Capello in 1672. Hence the 

 species that live in these lakes are of recent introduction. 



The author describes critically and with many references to 

 previous publications the freshwater and terrestrial species ob- 

 served, noting their distribution elsewhere, and any peculiarities 

 acquired, and describing many new species. The origin of the 

 distribution of the species is next considered, and the following- 

 are the more important conclusions reached. 



The terrestrial fauna of the Azores, is, as generally regarded, 

 strongly European ; and the freshwater fauna perhaps still more 

 strikingly so. The species in the fauna are those of extremely 

 wide distribution and many- are cosmopolites. 



Moreover they are kinds that are well furnished with means of 

 dissemination, and owe to this the circumstance that they have 

 reached the Azores. They seem for the most part to have been 



