256 MR. J. A. DOUGLAS ox GEOLOGICAL SECTIO>"S [vol. Ixxvii, 



The well-preserved oral lappet is similar in character to that of Hoplites 

 hyatti Stanton, from the Knoxville Beds of California.^ 



Hoplites (Acanthodiscus) cf. raimondi (Gabb)= Ammonites eaimon- 

 DiANUS Gabb. 

 This siib-genus makes its appearance in Europe in Lower Valanginian 

 times. 



Hoplites (Neocomites) cf. thurmanni Pictet & Campiche = Thur- 

 MANNIA THUEMANNi (Pictct & Campiche). 



This species is very abundant in the Mid- Valanginian of Europe (zone of 

 Kilianella rouhaudiayia (A. d'Grbigny),^ and continues into the Hauterivian. 



Hoplites (Leopoldia) cf. castellanensis A. d'Orbigny. 



This species is taken in Europe as the lowestsub- zonal index of the Lower 

 Hauterivian. 



Hoplites (Leopoldia) peruanus Lisson, originally described as Hoplites 

 leopoldi D'Orbigny var. peruana Lisson. 



A. d'Orbigny's species occurs in the Lower Hauterivian of Europe, sub-zone 



of Hoplites castellanensis D'Orbigny. 



Holcostephantjs (Spiticeras) cf. NEGRELi Matheron. 



A Lowep Valanginian form occurring in the zone of Hoplites (Thurmannia) 

 boissieri Pictet. According to Burckhardt, it is also found in the Spiticeras- 

 Beds of Mexico (Lower Valanginian). 



ScHLCENBACHiA (Nicklesia) cf. cuLTBATA A. d'Orbigny. 



A Lower Hauterivian form, sub-zone of Leopoldia castellanensis (D'Or- 

 bigny). 



Ancyloceras cf. SABAUDIANUM Pictet & Loriol=CRiocERAS (Leptocebas) 

 SABAUDIANTJM (Pictet & Loriol). 



A Barremian species. 



AucELLA sp. Originally figured and described as a Synclonema (Syncyclo- 

 nema). ^ 

 From the known distribution of the genus Aucella, its occurrence here 

 would not be expected. 



Having given a brief view of the development of the shallow- 

 water Lower Cretaceous deposits of the coastal region, I may now 

 proceed to a discussion of the plutonic rocks which, as seen in 

 the section, follow them on the east. 



In this district we once more traverse the great line of batho- 

 lithic intrusion which forms the core of the Andes throughout 

 Peru. Its occurrence has already been noticed in the extreme south 

 of the country, in the valley of the Llutah near Arica ; thence it 

 was traced northwards, past Tacna and Moquegua, to the Cerros 

 de la Caldera near Arequipa. During the course of the expedition 

 it was also met with at lea, and again in the district now described ; 

 while still farther north it was proved to occur in the region of 

 Trujillo, where it constitutes the sea-clif£s at Salaverry, and inland 

 fi'om Pacasmayo on the route to Cajamarca. 



1 Bull. U.S. GeoL Surv. 133 (1895) pi. xvi, fig. 2. 



2 W. Kilian, ' Lethsea Geognostica' p. 193. 



^ C. I. Lisson, ' Geologia de Lima, &c.' 1907, p. 31 & pi. iii, fig. 4. 



