274 Cephalopoda in Tate and Blake’s ‘Yorkshire Lias.’ 
The species Ammonites cequalis was described by M. Simpson (Foss. 
Yorkshire Lias, 1855, p. 49) as follows :• — ‘ Outer whorl nearly | the 
diameter, inner margin prominent ; radii equal, bend towards the 
aperture on the outer part of the whorl, nearly obsolete on the middle 
■of the back, not equal to the intervening spaces ; aperture ovate ; dia- 
meter, in. A cast with the centre broken ; probably from the lower 
lias. — Mr. Ripley’s Col.’ 
In the second edition of his work (published in 1884) Simpson (pp. 
80-81) transcribes his previous description, merely omitting the words 
■ Mr. Ripley’s .Col.’ 
Blake, who regarded this species as AEgoceras angulatum (Schlotheim), 
observes (Tate & Blake, ‘ Yorkshire Lias,’ 1876, p. 271) : ‘ The A. 
cequalis of Simpson is a peculiar form of the latter variety appearing 
from its matrix to come to [sic] slightly higher beds than usual, but it is 
only a fragment.’ It would appear, therefore, from this statement about 
the matrix that Blake had seen the type-specimen. 
In the Blake collection there is a fragment of an ammonite [B.M. 
-No. C. 18109], the internal cast of half of the outer whorl, 1*65 in. in 
diameter, with only traces of the inner whorls in the fractured surface 
filling the umbilicus, labelled in, what is believed to be, Simpson’s 
handwriting : ‘ A. sequalis. Lias. Yorks., no.' There is, therefore, 
great probability that this is the holotype of Simpson’s species that was 
originally in the collection of Mr. Ripley. Its exact locality in York- 
shire is unrecorded. 
AEgoceras charmassei d’Orbigny sp. (p. 272). 
There is no example of this species in the Blake collection. 
AEgoceras nanuml Martin sp. (p. 272). 
Blake (p. 272) writes : ‘ A minute single specimen (4 inch), from the 
A . angulatus — beds of Cliff, I cannot identify as the young of any known 
form, it has very similar characters to the small shell described by Martin, 
and quoted above . [i860. ‘ Palentologie Stratigraphique de l’ln- 
fralias,’ pi. i., figs. 3-5]. There are no ribs but swellings or knobs rather 
nearer the inner edge, and the front is smooth and round. In AE . nanum 
the knobs are on the outside, and the back is flatter.’ This specimen is in 
the Blake collection [B.M. No. C. 17938] and is represented in Blake’s 
PI. V., fig. 1 . , the outline figure indicating the natural size. The specimen 
was in a small round glass-topped box labelled in Blake’s handwriting : 
‘Ammonites nanus? Fig. i.Am.’ The name on the box originally 
read : ‘ Ammonites angulatus (Schl.) (young) ! ’ but the words ‘ angu- 
latus ’ and ‘ (young) ’ have, been crossed out, and the name ‘ nanus ’ ? 
inserted. Attached to the box was also another label in Blake’s hand- 
writing : ‘ PL A., fig. ' 1 ’ The specimen is not accompanied by any 
locality label, but fortunately the ‘ Geological position ’ is given by 
Blake — A . angulatus — beds of Cliff. 
AEgoceras longipontium Oppel sp. (p. 273). 
The Blake collection does not contain an example of this species. 
AEgoceras pauli Dumortier sp. (p. 273). 
The small block represented in Blake’s figure 4 A is in the Blake 
collection and includes two specimens [B.M. Nos. C. 17934 and C. 17935]. 
The block, represented in Blake’s figure of about the natural size, is 
labelled in Blake’s handwriting: ' PI. B., fig. 4.' and ‘ [Buckla]ndi. 
[Red]car. [A. se]micostatus A. Pauli,’ but the second label has been 
very much damaged. Referring to this species Blake remarks : ‘ It is 
represented by the lower specimen [B. M. No. C. 17934] of the two on 
the same stone,’ and for the ' Geological position ’ he gives : ‘ Zone of 
Naturalist 
