134 
SELACmi. 
1878. iHychodw nwmmiltavk, St. Ziirecznego, Sprawozdanie Komi.syi 
Fizyjograf. Galicyi, vol. xii. p. 201, pi. viii. fig. 9. 
188.5. Ptychodus mammilkiriis, 1*'. A. Quonstedt, Ilandb. Petrefakt. .3rd 
edit. p. 282, pi. xxi. figs. 01, 02. 
Type. Detached teeth ; British lluseum (in part). 
The crowns of all the teeth are much elevated, the transverse!)' 
ridged portion being sharply defined from the surrounding finely- 
marked area. The latter is relafivelv extensive, and the delicate 
rugae are mostly elongated, and concentric with the borders of the 
crown : this area is al.so often marked by radiating grooves. 
Form. ^ Loc. Senonian and Turonian ; S.E. England, France, 
Germany. Turonian and Cenomanian : Belgium, Bohemia, and 
Russia. Cretaceous: Delaware, U.S. A. (A;/«ss(‘r). 
Except where otherwise stated, the following specimens were ob- 
tained from undetermined horizons in the Upper or Lower Chalk : • 
4408, 4394-6. Four of the type-specimens figured by Agassiz, 
tom. cit. pi. 2.5 h. figs. 12, 14, 15, 18 ; Lewes, Sussex. 
Mantell Coll. 
25775, 28336. Two teeth figured by Dixon, oj>. ciV. ; Brighton, 
Sussex. Dixon Coll. 
28334. Sixteen naturally associated teeth and fragments in block 
of Sussex Chalk. Dixon Coll. 
28335. Three large teeth, and four smaller ; Brighton. 
Dixon Coll. 
4364, 4366-7. Three naturally associated series of teeth, one com- 
prising ten teeth and fragments, the second nine, and the 
third fourteen ; Lewes. Mantell Coll- 
4397, 4399, 4401, 4404, 4406, 4414, 4426-7, 4430-33, 4435-43, 
4447-8, 4450. Twenty-seven detached teeth ; Lowes. 
Mantell Coll- 
49838-9. Two groups of teeth, perhaps belonging to the same indi- 
vidual ; Glynde, near Lowes. Capron Coll- 
P. 5389. Group of eleven naturally associated teeth, with very 
broad marginal area, and six similar teeth (including one 
lower median), probably found with these ; Lewes. 
Presented by P. E. Coombe, Esq., 1888. 
