NEWTON AND HARRIS: BRITISH EOCENE CEPHALOPODA. 129 



referred to, though we caunot even recognise this as the type, because 

 the characters of the siphuncle are not ascertainable either from the 

 figure or description. The third species included by Conrad is the 

 English Tertiary shell, Nautilus Parkinsoni, Edwards, the structure of 

 which in all its details is so well understood that we have no hesita- 

 tion in finally regarding it as the type of Uercoglosm. We had 

 arrived at this conclusion before noticing that the late Dr. Paul 

 Fischer ^ had apparently been led to a similar result. 



Two years after the foundation of this genus, Conrad included in it 

 another species, the Aturia paucifex of Cope,* alluding to it in a list of 

 Cretaceous fossils from New Jersey as " Hercoglossa paucifex,'''' ^ a shell 

 which has been recently re-described, and figured for the first time by 

 Mr. E.. P. Whitfield.^ The genus ranges from Trias to Eocene times. 



Hercoglossa Parkinsoni, Edwards. 



^^ Nautilite,''^ Parkinson. — Organic Remains, 1811, vol. iii. p. 105, 



pi. vii. fig. 15. 

 Nautilus Parkinsoni, Edwards. — Mon. Pal. Soc. 1849, p. 49, pi. vii. 

 Hercoglossa Parkinsoni, Conrad. — American Journ. Conch. 1866, vol. ii. 



p. 101. 

 Nautilus f Hercoglossa J Parkinsoni, Poord and Crick. — Annals, 1890, 



ser. VI. vol. v. p. 389. 

 Aturia Parkinsoni, Poord. — Cat. Poss. Ceph. British Museum, 1891, 



part 2, p. 347. E. B. Newton. — Syst. List Edwards 



Coll. British Museum, 1891, p. 292. 

 This rare species, represented by only two specimens, was first 

 recognised by Conrad as belonging to his genus Hercoglossa, an opinion 

 subsequently adopted by Messrs. Poord and Crick, though in a 

 sectional sense. It attained to an enormous size and is probably 

 the largest known Tertiary nautiloid shell. The tubular and gradually 

 increasing nature of the siphuncle is well displayed in the Colchester 

 specimen, the shell having been removed for this purpose. These 

 details are observable at two periods of its growth, viz. at 2J inches 

 and at 1 1 inches diameter. This species, as before explained, we 

 regard as the type of Hercoglossa. 



Formation. — London Clay. Localities. — Harwich (type) and 

 Colchester. 



Hercoglossa Cassiniana, Poord and Crick. PI. X. Pigs. 4, 5. 



Aturia Cassiniana, Edw. MS. 



Nautilus [Hercoglossa) Cassinianus, Poord and Crick. — Ann. Mag. Nat. 



Hist. 1890, ser. VI. vol. v. p. 409, woodcut fig. 9. A. H. 



Poord. — Cat. Poss. Ceph. British Museum, 1891, pt. 2, 



pp. 333-4, woodcut fig. 70. 



Manuel Conchyliologie, 1882, p. 415. 



Proc. Acad. Nat. Sci. Philadelphia, 1866, pp. 3, 4 (not figured). 



Cook's "Geology of New Jersey," 1868, p. 731. 



Monographs United States Geol. 'Survey, 1892, vol. xviii. p. 246, pi. xxxix. fig. 1. 



