RAYMOND: SOME NEW ORDOVICIAN TRILOBITES. 289 



as they can be and still retain their circular shape. They appear to 

 be very large but superficial puncta. Along the borders these are 

 less numerous, and among them are numbers of short wavy cracks 

 roughly parallel to the margin. Exfoliated specimens of course show 

 no trace of this ornamentation but do show faint traces of ribs on the 

 pleural lobes. 



Measurements: — The largest pygidium is 43 mm. long and 57 mm. wide. 

 The a.xial lobe is 35 mm. long and 17 mm. wide at the front. A second .speci- 

 men is 33 mm. long and 45 mm. wide. The ratio of length to width indicates 

 the elongation of the pygidium in this species. This index in H. ulrichi which 

 is more like H. indentus than any other described species is about 610, in H. 

 obtusu.s it is 655 to 680, in H. elongatits, which has a long pygidium it is about 

 700, while in the largest specimen of H. indentus it is 754. 



Aside from the length of the pygidium and the upturned posterior 

 margin, the character of the ornamentation serves to identif\- this 

 species. 



Horizon .kkd Locality : — This seems to be a rather rare species, 

 found so far only in the Holston in the Catawba Valley, north of 

 Salem, and on the Hoge farm, nine miles southwest of Bland, Va. The 

 specimens from this latter locality were collected by Dr. E. W. Shuler. 

 Cot\-pes M. C. Z. 1,581, 1,582. ' 



HOMOTELUS LAEVIS, sp. nOV. 



This name is suggested for a species, the pygidia of which are com- 

 mon and of which a few fragmentary cranidia and free cheeks have 

 been seen. In general outline and proportions the pygidium is most 

 like that of //. ohtusus but the axial lobe is more strongly developed 

 and the pimcta are much fewer, finer, and farther apart. There is 

 also a faint concave border on the posterior part. The cranidium 

 is very slightly convex, the eyes large and well back. The cephalon 

 is in fact much more t\-pically isoteliform than that of any other 

 species. Exfoliated or compressed specimens show rather plainly the 

 ribs of the pygidium. 



Me.^surements: — A small pygidium is 22 mm. long and about 35 mm. wide. 

 The axial lobe is 16 mm. long and 11 mm. wide at the front. A large speci- 

 men (flattened) is 45 mm. long and about 70 mm. wide. 



This species is exceedingly common in the Athens at Chatham Hill, 

 on the northern slope of Walker ^Mountain, north of Marion, Va. It is 



