732 ‘PROF. REYNOLDS AND MR. VAUGHAN ON THE __ | Nov. 1902, 
some specimens of which the ribs in the left valve are markedly 
angular, but it is in that case a very extreme form. 
Belemnites att. ilminsterensis is a long, cylindrical, slowly-tapering, 
tripartite belemnite. 
(6) The Upper Lias. 
Lithologically, there are three distinct types of rock, all of which 
contain ammonites characteristic of this horizon. 
(1) A very compact, cream-coloured marl. 
In this bed, which is 2 or 3 feet thick, Ammonites falcifer is 
abundant, small Rhynchonelle are not infrequent, and Belemnites 
aff. vulgaris occurs occasionally. 
(2) A very compact, marly limestone charged with angular, 
jaspery fragments. 
In this bed, which is of about the same thickness as (1), Ammonites 
communis (and in particular one of its mutations, Amm. Holandrev) 
is extremely abundant; well-grown specimens of Amm. Levisoni 
also occur, while young forms of this, or an allied species of 
Hildoceratan ammonite, are plentiful. Rhynchonella Moorei occurs 
sparingly. In all probability we must assign to this horizon a very 
curious breccia, containing angular fragments embedded in a deeply- 
stained matrix. 
(3) A pyritous bed containing very numerous specimens of 
Ammonites bifrons. The majority of the specimens are fragmentary, 
rounded, and pyritized. 
The total thickness of the Upper Liassic beds probably does not 
exceed 10 feet. 
The following is a list of the fossils which we have obtained from 
these beds, without distinction of matrix :— 
Ammonites (Dactylioceras) communis, | Belemnites aff. vulgaris, Y. & B. 
Sow. and its mutation, Amm. Hol- — Pecten sp. 
andrei, V Orb. Rhynchonella Moorei, Davy. 
Anim. (Hildoceras) bifrons, Briig. Rhynchonella sp. 
Amm. (Hildoceras) Levisoni, Simps. Drift-wood is very common in the 
Amm. (Harpoceras) falcifer, Sow. | pyritous bed. 
Paleontological Notes. 
4 
‘The ammonite of the communis-group, alluded to above as 
Ammonites Holandrei, d’Orb. is the mutation so common at Stoke, 
near South Petherton. 
Amm. faleifer, Sow. is the species figured as Ami. serpentinus in 
Wright’s monograph on the ‘ British Lias Ammonites’ (Pal. Soc.). 
Rhynchonella sp, isa small form of the type of Rh. calcicosta ; we 
have not found enough specimens to ensure its determination. 
