part 1] ANNIVERSARY ADDRESS OE THE PRESIDENT. H 



Geological Survey of Portugal, then under the Directorship of 

 Prof. J. F. N. Delgado ; with that Survej^ he came to he connected 

 for the remainder of his life, a period of nearly 40 years. His 

 actual appointment to the Portuguese Survey was probably made 

 about 1885, although he was engaged in a temporary capacity 

 in 1SS0, when the Survey published his first memoir on the 

 ' Terrains Jurassiques du Portugal,' which embraced a stratigraphic 

 and palseontological account of the Liassic and Dogger rocks 

 occurring north of the Tagus. Then followed his memoirs on the 

 Jurassic palseontolog}*" of Portugal, in which he described the Pele- 

 cypoda and Cephalopoda, illustrated by nearly forty quarto plates, 

 the whole of which was issued in parts between 1885 and 1893. 

 In this he introduced the name ' Lusitanian ' for a group of rocks 

 lying between the topmost Calloviah and the Neo- Jurassic, a part 

 of which is rich in fossils, particularly the ammonite Perlsphinctes 

 and the pelecypod genus Trichites. 



The history of the Cretaceous rocks of Portugal claimed also a 

 large share of his attention, and his memoirs on those groups are 

 models of analytical enquiry and accuracy ; the essentially strati- 

 graphical part of the subject, occupying nearly 350 pages of text 

 and containing valuable faunistic tables, sections, and maps, was 

 published in 1885 and 1900. The strictly palseontological memoirs 

 dealing with the Cretaceous faunas were issued between 1886 and 

 1902, and, as before, the various life-groups, chiefly the Mollusca, 

 were profusely illustrated, described, and horizoned. 



The faunas of the Tertiary and later deposits of Portugal had 

 been mostly described by others, so that Choffat contributed only 

 a small amount of literature on this subject, although mention 

 may be made of his paper ' L'Homme Tertiaire en Portugal,' 

 published in 1880, which, however, never claimed particular atten- 

 tion on account of the imperfection of some of the details of the 

 subject. No notice of Choffat would be complete without a 

 reference to his work on the geology of the Portuguese African 

 possessions. His masterly memoirs of 1903 and 1905, dealing with 

 the Angola region of South- West Africa and the Mozambique 

 territory of South-Bast Africa, greatly contributed to solve many 

 interesting problems connected with the stratigraphy of those areas 

 of the African continent. 



On collateral subjects connected with the geology of Portugal, 

 he published communications respecting erosion, seismology, and 

 hydrology, besides compiling a series of most useful bibliographies. 



