.8^, NOTES AND COMMENTS. 415 



of the Society early in April. Since that date Professor Marsh, in his 

 Notes on Triassic Dinosauria [Amer. Jouvn. Sci., June, 1892), had 

 published, as regards Zanclodon, conclusions similar to those at which 

 the author (Professor Seeleyj had already arrived." 



In the Scottish Geographical Magazine for July, Dr. H. Schlichter 

 concludes his paper on the Pigmy Tribes of Africa, and gives a map 

 showing their distribution. The map shows that with the exception 

 of a few scattered races between 15° and 25° S. latitude, the whole 

 of the tribes are confined to the district between 5°N. and 5° S. lat., i.e., 

 to the Gaboon Coast, the forest area of the Congo State, the west side 

 of the Albert Nyanza and the north of Lake Rudolf. The paper is an 

 excellent epitome of our present knowledge of these peoples, and is 

 abundantly supplied with references to other authors. Professor James 

 Geikie's paper, read to the Society on May 18th, on Recent 

 Researches in Pleistocene Climate and Geography, is printed in the 

 same magazine ; it is accompanied by a map of Northern Europe, 

 showing the areas covered by ice during the epoch of maximum 

 glaciation, and by the great Baltic glacier and the local ice-sheets 

 of Britain at a later date. 



The question of the action of light on the colouring of vertebrate 

 animals is dealt with by Sr. A. L. Herresa in a paper — " El Elima 

 del Valle de Mexico y la biologia de los vertebrados," in La 

 Naturaleza (t. ii., c. 2), issued last month. The paper, which partly 

 appeared in the previous number, deals with the production of colour 

 by light reflected by coloured bodies, the modification or production 

 of colours by white light or by reflected light, and terminates with a 

 long series of conclusions and a short paper on the general influence 

 of light. In the same number of La Naturaleza there is a paper, 

 " Apuntes para la Geologia del Valle de Mexico," by G. B. y Puga, 

 dealing with the eruptive mass of El Penon de los Baiios, some four 

 kilometres east of the City of Mexico. The hill consists of two 

 roughly semicircular masses, one of volcanic agglomerate, and the 

 other of Retinitic-Andesite, with an included mass of black basalt 

 and an outer fringe of a similar rock. Analyses of the rocks are 

 given, and several illustrations from photographs assist the reader. 

 Some notes are printed by A. Duges on Dendroica dugesi, H. K. Coale, 

 the passerine bird described as new in 1887, which show that it should 

 rather be regarded as referable to D. (estiva (Gm.). Jose N. Rovirosa 

 contributes a " Calendario botanico de San Juan Bautista y sus 

 Alrededores, ano de 1890," which, assisted by a chart, gives the times 

 of flowering and other interesting information, including the local names 

 so often of assistance (or hindrance) in determining plants. A variety, 

 flovibanda, of Brewevia mexicana, Hemsley, is described and figured by 

 M. M. Villada. 



