24 BRITISH FOSSILS. 



of part of the toothed edge of another appendage (c") is discerni- 

 ble. It is turned backwards (so that it is certainly displaced), and the 

 teeth are somewhat curved and striated. If there are two endo- 

 gnaths on each side, this might well be one of the left pair turned 

 round. 



On the left-hand side, the palp (e] of the ectognath is in position, 

 but nothing is to be seen of its basal joint. On the right-hand side, 

 the large basal joint of an ectognath lies detached and turned round, 

 so as to have its cutting edge directed backwards. A confused mass 

 occupies the place of its palp. 



Where the antennse should be there is, on the left side, a long and 

 broad dark impression (6) fading away externally. On the right side 

 there is a somewhat similar marking which continues the line of 

 that on the left hand, but is very broken and irregular. However, 

 it divides distally into two branches, on the opposed edges of which 

 the remains of the characteristic antennary teeth can readily be 

 discovered (6'). 



Whether these impressions represent one antenna, or portions of 

 both, I cannot say, but between them, and in front of them, a dark 

 sculptured area (/) presents itself, which is cut off anteriorly by the 

 fractured edge of the stone. On the right side, this area is bounded 

 by a well-defined margin, which runs between the posterior boun- 

 dary of the antenna, and the inner of the two endognaths. On 

 the left side, its well-marked curved boundary is distinguishable 

 between the antenna and the broken edge of the stone. 



Towards the junction of the middle and anterior thirds of the left 

 lateral edge, a long, flattened, filiform appendage (c) comes off from 

 the carapace. On the right side, the remains of two such appen- 

 dages, with, perhaps, traces of a third, are visible (x). They come 

 off close to the two endognaths, and one might be inclined to 

 suppose them all organically connected with the latter, were it not 

 for the independent appendage on the opposite side. 



In the other, smaller, half of the specimen the only points to be 

 noted are, the greater distinctness of the right boundary of the 

 "sculptured area" in front of the carapace, and of the right (here left) 

 filiform appendages. I am strongly inclined to think that the 

 " sculptured area " in this fossil is the epistoma. The interpretation 

 of the filiform impressions is more difficult. That on the left side 

 seems to be attached directly to the carapace, and in that case might 

 be a second antenna. If this be its nature, the impressions on the 

 other side may be the corresponding appendage and the palps of the 

 endognaths. On the other hand, it must be remembered that there 



