20Q 
NOTES AND COMMENTS. 
TYPE AMMONITES. 
S. S. Buckman’s Monograph on Type Ammonites continues 
to appear. Part XXXII. contains 20 plates, illustrating 17 
species, of which 9 are new. Since the completion of Vo 1 . III. at 
the end of 1921, Mr. Buckman has given us only plates without 
explanatory text. We may, however, draw certain inferences 
as to the development of his ideas from the notes incorporated 
in the plate-titles. We find that the majority of ammonites 
figured belong to two geological * ages ■ — Proplanulitan and 
Macrocephalitan. The former is the time of deposition of 
the Kellaways Clay and Kellaways Rock of England, and a 
tabulation of its hemerse and faunas was given a year ago, 
‘ Macvocephalites cf. arcticus, Newton. “ South Cave, S. Yorks. ; 
Kellaways Rock,” siliceous, ironshot. Mr. Frank Petch, coll. ; 
S. 33. 45, 72— ; 44* 45-5, 65 ; 22 + — ; size 51 ; ribs 22 ; max. c. 55. 
Fam. Macrocephalitidce , nov. Catacephalites durus, nov. Macvo- 
cephalitan, Catacephalites ; Genotype; Holotype. Cf. CCLXXIII.’ 
though apparently an additional hemera (Galilaeites) will have 
to be interpolated now. The Macrocephalitan age is evidently 
the old macrocephalus zone, represented stratally partly by 
Cornbrash and partly by Kellaways Rock : in this the author 
recognizes at least five hemerse, though at present he gives no 
hint of their relative date. We are kindly permitted to re- 
produce of one of the Yorkshire species, Catacephalites durus, 
n.sp. from South Cave : this is dated as Macrocephalitan, 
hemera Catacephalites. The plain meaning of this statement 
is that the ‘ Kellaways Rock ’ of South Yorkshire is, in part 
at least, older than any part of the ‘ Kellaways Rock ’ of 
1922 July 1 
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