282 ME. J. A. DOUGLAS OX GEOLOGICAL SECTIONS [vol. Ixxvii, 



(44) 1897, K. Geriiardt. — ' Reitrag zur Keimtniss dei* Kreidefovmatioii in Vene- 



zuela & Peru.' Xeues .Jahib. Beilageband xi, p. 65. 



(45) 1903. W. Paui.cke. — ' Ueber die Kreidefovmation in Siidamerika & ihve Bezie- 



liungen zu anderen Gebieten.' Xeues Jabvb. Beilageband xvii, p. 252. 



(46) 1904. G. Steix-MANX,— ' 01)servaciones Geologicas efectuadas desde Lima liasta 



Cliancliama^'O.' Bol. Cuevpo Ing. Min. Peru, No. 12. 



(47) 1904. Caelos I. Lisson. — ■' Los Tigillites del Salto del Fraile & algunas Son- 



neratia del Morro Solar.' Bol. Cuerpo Ing. Min. Peru, No. 17. 



(48) 1907. C. I. LissoN. — ' Contribucion a la Geologia de Lima & sus Alrededores.' 



Lima, Peru. 



(49) 1908. C. L LissoN. — ' Contribucion al Conocimiento ?obre algunos Ammonites 



del Peru.' Lima, Peru. 



(50) 1912. OiTO SCHLA.&INTWEIT. — ' Die Fauna des Vracon & Cenoman in Peru.' 



Neues Jalirb. Beilageband xxxiii, p. 43. 



(51) 1913. C. L LissoN. — ' Edad de los Fosiles Peruanos & Distribucion de sus 



Depositos en la Kepublica.' Lima, Peru. 



(52) 1913. L. SoMMERiiEiER. — 'Die Fauna des Aptien und Albien im nordliclien 



Peru.' Neues Jalirb. Beilageband xxxvi, pp. 370-412. 



(53) 1920. J. A. Douglas. — 'Geological Sections through the Andes of Peru & 



Bolivia: II — From the Port of Mollendo to the Inambari River.' 

 Q. J. G. 8. vol. Ixxvi, pp. 1-61. 



EXPLANATION OF PLATES XV-XX. 



Plate XV. 



Figs. 1 a & 1 &. Terehratida (Lohothyris) cf. ovatissima Quenstedt (obese 

 variety). Lower Lias. Charata, near Oroya, Peru. 

 (Natural size ; see p. 264.) 



Fig. 2. Do. do. (elongate variety). Lower Lias. Charata, near 



Oroya, Peru. (Natural size ; see p. 265.) 



3. Do. do. Anterior view, showing ' rectimarginate ' stage of 



growth. (Natural size.) 



4. Do. do. Anterior view, showing " uniplicate ' stage of growth. 



(Natural size.) 

 Figs. 5 & 6. Do. do. Anterior views, sho'wing ' sulcipliciite ' stage of 



growth. (Natural size.) 

 Fig. 7. Ti'igonia lorentii Dana. Neocomian. Isle of San Lorenzo, Callao, 



Peru. (Natural size ; see p. 253.) 

 Figs. 8a & 8 5. ScMcenhacliia ventanillensis (Gabb). Albian. Saco, near 



Oroya, Peru. (Natural size ; see p. 270.) Young form, 



showing transition from smooth to costate stage. 



Plate XVI. 



Fig. 1. Schlcenhachia sp. {oi. acutocarinata [Shumard] Bose). Albian. Saco, 

 near Oroya, Peru. (X |; see p. 269.) Specimen showing ribbing 

 of cast. 



2. Schlcenhachia multijida Steinmann. Albian. Saco, near Oroya, Peru. 



(Natra-al size ; see p. 267.) Specimen showing the natiu-e of the 

 ribbing in the cast of a young individual, and smooth shell preserved 

 on the inner whorls. 



3. Do. clo. (X h.) Mature individual with shell preserved, 

 except near the mouth. 



4. Do. do. (Natural size.) A portion of the same individual, 

 showing the true nature of the ribbing on the shell. 



5. Do. do. (Natural size.) Peripheral view of a young indi- 

 vidual. 



