156 



possess the characters of Dikelocephalus, and we cannot, there- 

 fore, with the evidence at our command, justly consider these 

 as parts of one and the same Trilobite. Should future 

 researches show them to be so, then we possess a form with a 

 cephalic shield resembling that of Conocephalites, more or less, 

 and a tail almost undistinguishable from Dikelocephalus. 

 Such a combination of characters would clearly demand the 

 creation of a new genus for their fossils in question. 



Genus ASAPHUS Brongniart, 1882. 



(Hist. Nat. Const. Foss., P. 17.) 



ASAPHUS. sp. a. (Fig. Q.j 



Ohs. A pygidium, measuring sixteen lines by eleven, is pre- 

 served in so far that the central axis, one entire wing, and a 

 portion of the other, with the concave margin are present. 

 The latter bears very faint indications of the concentric strioe 

 usually seen around the tail of Asaplms. The full width of 

 the tail would probably have been about eighteen lines. 

 ASAPHUS. sp. h. {Fig. 5.) 



Obs. A pygidium with a convex surface, and a generally 

 robust appearance. The axis is large, and shows traces of 

 numerous broad segments. It is a squarer and less oval form 

 than in the last species, and the limb is wider and more con- 

 cave. 



It is possible from the general contour and appearance of 

 these specimens that they represent distinct species. 



With remains so fragmentary, it is unnecessary to attempt 

 a comparison with known species. 



The remaining Trilobites are in too fragmentary a condition 

 to determine satisfactorily. I shall, therefore, merely describe 

 them as far as the material will allow, and indicate the 

 direction in which their af&nities probably lie. 



1. A head shield with an ;>bloagroundedly-convex glabella, 

 ornamented with granules, rounded in front, and reaching far 

 forward almost to the anterior margin of the head. The 

 furrows are two in number, the anterior pair very faint (in the 

 cast), and almost transverse, the hinder pit-like and rather 

 more oblique ; the axal furrows are deep, but gradually become 

 shallower forwards. The fixed cheeks are broad towards the 

 posterior part of the head, and appear to narrow forwards, 

 forming a limited space of demarcation between the 

 anterior part of the glabella and the front margin ; 

 the latter is strong and well marked. No definite description 

 can be given of the facial suture, unless what appears to be 

 a defined margin on the right-hand side of the head is it. 

 (Figs. 8 and 9.) 



I am unable to satisfactorily refer this Trilobite to any 

 known genus, and I suspect it will constitute a new form, 

 possessing some of the characters used in Hall's definition of 



