MADE BY DR. ANTONIO RAIMONDI IN PERU. 311 



A. CERAS, Giebel, Fauna der Vorw., Cepli., p. TSY. 



Arnioceras id., Hyatt, Proc. B. S. N. H., v. It, p. 366. Lias.; Peru. 



A. CoDAZZiANUS, Karst., Geog. Verli. N. Gren., p. 108, PI 3, f. 4, 5. Cret.; Col. 



A. CoLOMBiANUS, d'Orb., Am. Mer., p. 17, PI. It, f. 12-14. 



Id. d'Orb., Foss. Coll., p. 41, Pi. 2, f. 12-14. Cret.; Colombia. 



A. COMMUNIS, Sby., M. Con., PI. lit, f. 2-3. 



Id. Phil., Atacama, p. 141. Lias.; Cliile. 



A. cORNirERUS, Gabb, new sp. Jur. ; Peru. 



A. Damsiands, d'Orb., A. Mer., p. 69, PI. 2, f. 1-2. 



Id. d'Orb , Foss. Col., p. 33, PL 2, f. 1-2. Cret.; Col. 



A. DoMEYKANUS, B. & C, M. G. S. Fr., 2 s., v. 4, p. 10, PL 2, f. 3-5. 



Id. Hup., Gay's Chile, p. 36. ' Lias.; Chile. 



A. DuPiNiANCS, d'Orb., P. Fr., T. Cr., p. 2t6, PL 81, f. 6-8. 



Id. Karst., G. Verb. N. Gren., p. 412, PL 5, f. 5. Cret.; CoL 



A. riMBRiATUS, Sbj^, M. Con., v. 2, p. 145, PL 164. 



Id. Hup., Gay's Chile, p. 23. Jur.; Chile. 



A. GALEATus, V. Buch, Petr. rec. par Huml)., p. 12, PI. 2, f. 20. 

 Id. d'Orb., Am. Mer., p. t5, PL It, f. 3-t. 



Id. d'Ob., Foss. Col., p. 3T, PL 2, f. 3-t. 



A. Tocaymensis, Lea, Tr. A. Phil. Soc, 2 s., v. 7, p. 253, PL 8, f. 2. Cret.; Colombia. 



A. Americanus, Lea, loc. cit., p. 255, PL 8, f. 6. 



A. compressissimus, d'Orb., Pal. Fr., T. Cr., v. 1, p. 210, PL 61, f. 4-5. 

 A. Didayanus, d'Orb., loc. cit., p. 360, PL lOS, f. 4-5. 

 A. Leai, Forbes, Quart. Jour. Geol. Soc, v. 1, p. It8. 

 A. galeatoides, Karst. Yerh. N. Gren., p. lOt, PL 3, f. 1. 

 A. caicedi, Karst., loc. ciL, p. lOt, PL 3, f. 2. 



A. Lindigii, Karst., loc. cit., p. 108, PL 3, f. 3. Cret.; Col. 



A. Gati, Gabb. 



A. tripartitus, Huppe, Gay's Chile, p. 35, PL 1, f. 2. 



Not A. triparlitus, 'Raspail. Jur.; Chile. 



This resembles A. Boussingaultii., d'Orb. (Cretaceous), but the two authors place their s|)e- 

 cies in different formations. Apart from tliis, which may be an error on the part of one or the 

 other, the species differ, according to the figures, in tliis species having fewer nodes on the middle 

 of the whorl, and in each node sending a rib to the suture. The figure of d'Orbigny's species 

 makes the umbilical half plain. Nevertheless, I have seen such great variation in the surface 

 ornaments of the same species of Ammonites that, had the two forms been referred to the same 

 geological age, I should have preferred calling the two by one name. 



A. GEMMATUS, Hup., Gay's Chile, p. 35, PL 1, f. 3. Jur.; Chile. 



A. GiBBONiANUS, Lea, Tr. A. P. S,, 2 s., v. t, p. 254, PL 8, f. 3. - ■ 



Id. Hyatt, Hartt's Brazil, p. 389. 



Id. Gabb, present paper. Cret.; CoL, Peru, Brazil. 



The North American form referred to this by Marcou and subsequent authors is a distinct 



but allied species. It increases much more rapidly in the size of the whorls, and they have a 



