HISTORY OF INVESTIGATIONS 641 



unidentified ammonites and noted the occurrence of several Jurassic 

 genera. The existence of Jurassic strata could no longer be doubted, 

 although the exact age of the formations was at that time still unknown. 

 The general results of De la Torre's discoveries were incorporated in the 

 statement prepared by Vaughan for the memoir of the "Stratigraphy of 

 North America/* in which reference is made to the occurrence of the 

 genus Idoceras [in all probability Perisphinctes] in the rocks of the 

 Organ Mountains in Pinar del Eio. 7 



In 1911 Mr. Brown visited Cuba to make collections of Pleistocene 

 vertebrates, and while in Havana received some ammonites from De la 

 Torre. On four subsequent excursions to the island the geology of the 

 western provinces was studied, large collections were obtained — the last 

 being in 1919 — numerous cross and columnar sections were made, and 

 the structure and general relations of the formations were worked out. 

 Up to the present time the authors have prepared the following papers 

 on the geology and paleontology of the Jurassic of Cuba. In 1918 

 the discovery of the Oxfordian beds at Vinales was announced 8 and, 

 as a part of the results of the paleontological studies, a paper on some 

 of the Cuban Perispliinctes was published (1919). 9 The progress of 

 the geological work done during 1919 and 1920 was incorporated in 

 three papers dealing with the details of correlation, 10 the broad geological 

 features and field relations, 11 and some of the upper Oxfordian and lower 

 Lusitanian ammonites of the Vinales region. 12 Further paleontological 

 results have been brought out in a paper on the Aptychus shales of the 

 San Vicente section 13 and one on the Cuban species of Ochetoceras, in- 

 cluding a general phyletic study of the European and American repre- 

 sentatives of that genus. 14 



In 1920 Dr. Mario Sanchez Roig published a paper on the Jurassic 

 of Vinales in -which he listed and illustrated forty-seven species of 



7 Bailey Willis: Index to the stratigraphy of North America. Professional Taper No. 

 71. 1912. (See p. 552.) 



8 Barnum Brown and Mar.iorie O'Connell : Discovery of the Oxfordian in western Cuba. 

 Bull. Geol. Soc. Am., vol. 30, 1919. p. 152 (abstract). Presented December, 1918. 



9 Mar.iorie O'Connell : Orthogenetic development of the costse in the Perisphinctina?. 

 Am. Jour. Sci.. vol. xlviii. 1919, pp. 450-460, 2 figs. Presented before the Paleontolog- 

 ical Societv of America Dpcpmher. 1918. 



10 Marjorie O'Connell : Further studies on the Jurassic of Cuba. Bull. Geol. Soc. Am., 

 vol. 31, 1920. p. 136 (abstract). Presented December, 1919. 



11 Barnum Brown : Cuba. Eleven pages, 57 illustrations, including maps, sections, pho- 

 tographs, 1920. (Privately printed.) 



3 - Marjorie O'Connell : The Jurassic ammonite fauna of Cuba. Bull. Am. Mus. Nat. 

 Hist., vol. xlii. 1920, pp. 643-692, plates xxxiv to xxxviii. 



] " Marjorie O'Connell : New species of ammonite opercula from the Mesozoic rocks of 

 Cuba. American Museum Novitates, No. 28, 1921, 15 pp., 18 text figures. 



14 Marjorie O'Connell : Phylogeny of tne ammonite genus Ochctoceras. Bull. Am. Mus. 

 Nat. Hist., vol. xlvi, 1922, pp. 387-411. 



