SUPPLEMENT.— LILLI A. xiii 



The species like Lilli are only sparingly found in this county ; and in some 

 cases the containing deposits are so thin that the faunal sequence is made out with 

 difficulty. In the Cotteswolds, where there is some thickness of deposit, they do 

 not occur ; but contemporaneity is established by their companion, the leptogyral, 

 snbangust-umbilicate development of HUdoceras bifrons. 1 



The forms like Lilli seem to belong to the Mediterranean borders and the 

 Rhone basin. It would be interesting to know if their position in those places 

 corresponds to that set forth in the above table. 



Family— HILDOCERATIM}. 



I. Genus — Lillia, Bayle. 

 1889. Ltllia. This Monograph, p. 108 (pars). 



Definition. — Steuogyral, latumbilicate, nodate, subrursi-recticostate, septi- 

 carinate, snbpauciseptate, inornatilobate. 



Remarks. — The nodi when present are situated near the edge of the inner 

 margin of the whorl. They are not strongly developed, and they disappear in 

 the gerontic stage while the costse are still present. 



Correction. — The solid carina described at p. 108 was an error partly due to 

 incorrect drawings in the works of certain authors, partly to a wrong identification 

 of "sulcata" as a Lillia. The carina is evidently hollow, as may be seen in 

 Supplement, PI. I, fig. 2, where a portion of the preserved infilling is shown. 



History. — The title Lillia was given by Bayle to an Ammonite which he 

 called " Lillia Lilli (Hauer) ;" 2 but it is not Hauer's species. Subsequently it was 

 used by Haug for the groups of A. comensis, von Buch, and A. Mercati, Hauer. 3 

 Later it was employed by myself as title for a genus, with A. comensis for the type. 



More critical consideration of generic characters makes it doubtful if such an 

 interpretation was justified. It seems probable that the Mercati-group has 

 nothing to do with the Llllia-Haugia series ; while the comensis- group, so far as 

 may be judged from von Buch's not very satisfactory figure, appears to be easily 

 separable from Bayle's Lilli by possessing the character of flexed ribs. 



Therefore it appears desirable to take as the type-form of Lillia the species 

 which Bayle figured as Lillia Lilli, though it is not Hauer's species, as it is more 

 densicostate. 



1 Cf. this Monograph, PI. xxii, figs. 30, 31. 



2 Op. cit., pi. lxxxii, fig. 1. 



5 ' Beitr. Monogr. Harp. Neues Jahrb. Mineral.,' Beil.-Bd. iii, p. 637. 



