Cephalopoda in Tate and Blake’s ‘ Yorkshire Lias.’ 279 
JEgoceras grenouillouxi d’Orbigny sp. (p. 280). 
Although there are no examples in the Blake collection definitely 
referred to this species, there are two pyritised specimens which Blake 
may have regarded as belonging to d’Orbigny’s species. One of.these- 
[B.M. No. C. 19223], the smaller of the two, 2i'2 mm. in diameter, is. 
labelled in Blake’s handwriting : ‘ Am. beds,-R.H.B.’ The peripheral 
portion of the outer whorl is well shown, also the umbilical margin on 
one side, but the umbilicus is obscured on each side by matrix. At its 
greatest diameter the whorl is 10 mm. wide, and in the last half whorl 
there are 15 transversely -elongated tubercles. The larger example 
[B.M. No. C. 19224] is 38‘6 mm. in diameter, but the last portion of 
its outer whorl is abnormally inflated, possibly owing to pyrites ; at 
the diameter of 31. mm. the thickness of the whorl is 12.4 mm. and in 
the last half -whorl at this diameter the lateral area bears 15 transversely 
elongated nodes and about three intermediate ribs, which do not bear 
tubercles. The specimen bears no original label, but its matrix and mode 
of preservation are precisely similar to those of the smaller specimens. 
The ‘ Geological position ’ of the Yorkshire representatives of this 
species is given by Blake as : ‘ Zone of A. jamesoni, Robin Hood’s 
Bay.’ 
JEgoceras striatum Reinecke sp, (p. 281). 
The Blake collection contains a Yorkshire ammonite [B.M. No. 
C. 18117] answering to Blake’s description of this species. It is a coarsely 
ornamented form, 70 mm. in diameter, labelled in Blake’s handwriting : 
‘ A. henleyi, R. Hood’s B.,’ but it does not agree with Blake’s interpreta- 
tion of that species. 
A Egoceras henleyi J. Sowerby sp. (p. 281). 
In the Blake collection there is an ammonite [B.M. No. C. 18118]/ 
97 mm. in diameter, answering to Blake’s description of this species. 
The specimen is not localised, but the matrix of the fossil and its mode 
of preservation, would, on comparison with the specimen above referred 
to AEgoc. striatum [B.M. No. C. 18117], lead one to suppose that the 
two fossils came from the same locality and horizon. Blake, however, 
gives for the ‘Geological position’ of AEgocer as striatum : ‘ Zone of 
A . jamesoni (rare at the top), Robin Hood’s Bay, Rockcliff, Huntcliff:,’ 
and for that of AEgoceras henleyi : ‘ Zone of A . capricornus , Huntcliff, 
Robin Hood’s Bay.’ The ‘ Geological position ’ then of the fossil is 
uncertain . 
.Egoceras hechei J. Sowerby sp. (p. 281). 
The Blake collection does not include a Yorkshire example of this 
species . 
AEgoceras capricornum Schlotheim sp. (p. 281). 
Respecting this species, Blake states : ‘ This is a rather variable 
species in respect to the strength of its ribs, which in some grow to an 
enormous, size, so as to double the section of the whorl taken through 
them, and pass quite straight over the front ; in others they are depressed 
on the front and grow rather oblique.’ The Blake collection contains a 
specimen [B.M. No. C. 19225], labelled in his handwriting : ‘ A. capri- 
cornus, R. Hoods B.,’ having- exceedingly strong ribs, as described by 
Blake. It is 58 mm. in diameter, its thickness through the ribs being 
25 mm., and between the ribs 19-5 mm. The collection includes also 
another fossil [B.M. No. C. 19226], the diameter of which is 56 mm. ; 
its thickness, through the ribs 17 mm., and between the ribs 14*2 mm., 
having its ribbing rather oblique. The specimen is not localised, but 
its matrix and mode of conservation are the same as the strongly -ribbed 
form already mentioned. 
There is a specimen [B.M. No. C. 18064] in the Blake collection, 4 
1922 Aug. -Sept. 
