262 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
been interchanged, for the specimen having the wide barder in front 
is labeled A. romingeri, while the description states that A. wiscon- 
sensis has the wide border. With the exception of this single char- 
acter, the width of the flat border in front of the glabella, the two types 
are in perfect agreement. Raymond and Narraway, without seeing 
the types, hazarded the opinion that Walcott’s two names represented 
only one species, and cited the fact that in their collections, the border 
was wider in young specimens than in older ones. It is true that the 
type of Asaphus romingeri is larger than that of A. wisconsensis, but 
the other specimens in the collection fail to bear out our suggestion. 
Beside the type, there is only one other specimen which will answer 
the} definition of Asaphus romingeri, and that is somewhat smaller 
than the type of A. wisconsensis, while there are several specimens of 
A. wisconsensis which are larger than the type of A. romingert. This 
difference in the width of the border certainly does exist among adult 
specimens, and while it does not seem to be of specific value, it is a | 
character which may later prove of use. | 
Clarke’s types of Ptychopyge ulricht were two pygidia from Cannon’s 
Falls, Minnesota, and they agree with pygidia from Platteville, Wis- 
consin, and Newport, New York, except that a complete pygidium of 
the same size as Clarke’s large fragment shows a much shorter form 
than is indicated by his outline restoration. 
The collection of the M. C. Z. contains, beside the specimens in the | 
Walcott collection, which are all from Russia (Newport), New York, | 
a number of cranidia and pygidia, and one nearly complete specimen, | 
from Platteville, Wisconsin. ‘The specimens in the Walcott collection — 
were presumably all used in describing Asaphus romingeri and A. wis- 
consensis, although there are pygidia present, a fact not mentioned in | 
the original descriptions. 
The nearly entire specimen is flattened, and is somewhat imperiane| 
in several particulars, but shows fairly accurately the general propor- | 
tions of the animal. The cephalon is large, occupying .43 of the length 
of the animal, while the thorax occupies .27, and the pygidium .30. 
The axial lobe is narrow, .32 of the total width, and the cephalon and, 
pygidium are both nearly semicircular, the length of the cephalon 
being .55 of the width, and the length of the pygidium .53 of the width. B 
These general proportions accord very well with a specimen of Tsotelus 
gigas 3.5 mm. long, except that the thorax being complete in the 
Basilicus, it makes the whole animal longer. iti 
Separated cranidia from St. Joseph Island, Lake Huron, (in collec: 
tion of the Geological survey of Renee from Ottawa, Onto, if q 
ar 
| 
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