294 Messrs. W. K. Parker and T. R. JoneS bn the 



D'Orbigny unnecessarily gives to Defrance's figaires the name 

 R. GerviUii (Ann. Sc. Nat. vii. p. 274, No. 36; Modeles, No. 72. 

 This model is admirable, like most of the others, for its charac- 

 terization) . 



Lamarck is not correct in referring this form to Plancus, 

 Conch. Min. Notis, pi. 1. f. 1 (which is R. Beccarii). 



7. Rotalia. Ann. Mus. v. p. 183. Rotalites trochidiformis. 

 Ann. Mus. v. p. 184, No. 1 ; viii. pi. 62. f. So,b; Tabl. Enc. 

 Meth. pi. 466. f. Sa,b; Hist. An. s. Vert. vii. p. 617. " Fossil ; 

 Grignon.^' [Defrance adds, as localities, Fontenai-Saints-Peres 

 and Hauteville, Diet. Sc. Nat. xlvi. p. 303,] 



This is one of the largest Rotalia, and is the most developed 

 form of the group which is typified by R. Turbo, d'Orb. A very 

 much better figure is given in the 'Diet. Sc. Nat.' Zool. pi. 14, 

 f. 3 a, b, c. This well-grown shell shows faintly the septal 

 markings on its strong, low, conical spire; on the other or 

 umbilical face, which is flatter, the chambers are covered with 

 granules and separated by deep chinks, margined by larger 

 tubercles, such as fill up and overgrow the umbilicus, sometimes 

 leaving evidence of irregular, astral, intercalated lobes or cham- 

 bers, sometimes masking the w^hole of the surface. This is the 

 R. obscura, Sowerby (Dixon's Foss. Sussex, p. 162, pi. 9. f. 6), 

 and R. Neuboldii, d'Arch. & Haime, Foss. Num. del'Inde, p. 347', 

 pi. 36. i.\7 a, b, c. 



We have not yet found this gigantic variety of R. Turbo re- 

 cent, although R. Turbo and very large specimens of the variety 

 vesicularis are extremely abundant on the coast near Melbourne, 

 Australia. 



This extreme form of R. Turbo is paralleled in development 

 by a large and strongly tuberculate variety of R. Beccarii (var. 

 Schroeteriana, nob.) ; by certain thick and granulate subvarieties 

 of Planorbulina vulgaris (var. lurvata, nob.), in which tlie original 

 features arc masked ; and by PohjstomeUa craticulata, — the 

 extreme development of P. crispa and the giant of the Foly- 

 stomellce. 



8. liotalites lenticularis (and a sinistral variety). Ann. Mus. 

 y. p. 184, No. 2. "Fossil; Grignon." 



Probably a flattish and rather delicate R. Turbo, with slightly 

 developed astral flaps. Such a form we find abundantly, fossil 

 at Grignon, and recent on the Australian shores. 



9. llotalites depressa. Ann. Mus. v. p. 185, No. 3. '' Fossil; 

 Grignon." 



I^his answers well to some of the large Truncatuline varieties 

 of Planorbulina farcta : we find many of these in the Calcaire 

 grossicr and otlicr French Tcrtiaries. 



10. llotalites Discorbula. Ann. Mus. v. p. 185, No. 4 ; viii. 



