RAYMOND: ISOTELUS GIGAS DEKAY. 261 
segments together measure 112 mm. in length. If this specimen had 
the same proportions as the one from Toronto, it would, when com- 
slete, have been 384 mm. long, and 260 mm. wide at the genal angles, 
thus giving a very large surface area. 
BASILICUS BARRANDI (HALL). 
Plate 1, fig. 4, 5; Plate 2, fig. 1, 7. 
Asaphus barrandi Hall, Foster and Whitney Rept. Lake Superior land dist., 
1851, pt. 2, p. 210, pl. 27, fig. 1, a-d; pl. 28. Geol. Wisc., 1862, 1, p. 41, 
fig. 4. 
Asaphus romingeri Walcott, 28th ann. rept. N. Y. state mus., 1879, p. 78. 
Asaphus wisconsensis Walcott, Ibid., p. 79. 
Ptychopyge ulrichi Clarke, Pal. Minn., 1897, 3, pt. 2, p. 709, figs. 12, 13. 
Basilicus romingeri Raymond and Narraway, Ann. Carnegie mus., 1910, 7, 
p. 49, pl. 15, fig. 9, 10; pl. 16, fig. 1-4. 
When Raymond and Narraway wrote, they did not have access to 
the Foster and Whitney report, or they would probably have adopted 
Hall’s name for this rather common Black River Basilicus. In view 
of the remarkable resemblance of the young of Jsotelus gigas to the 
adult of this Basilicus, it deserves to be more adequately figured than 
it has been hitherto. The species seems to be of wide geographic and 
narrow vertical range, and should be better known than it is. 
Hall’s types of Asaphus barrandi consisted of an entire specimen with 
the cephalon mutilated and showing the hypostoma in place, two 
imperfect pygidia, a free cheek, and a good pygidium. These speci- 
mens are preserved in the American museum of natural history, 
where I have had the opportunity to study them, through the courtesy 
of Dr. E. O. Hovey, Curator of Geology. Four of the specimens, 
(Hall, Loe. cit., pl. 27, fig. 1b, c, d, and pl. 28), including the entire 
specimen, are from Platteville, Wisconsin, and one, (pl. 27, fig. 1a), 
's from St. Joseph Island, Ontario. Platteville may, then, be con- 
sidered the type locality for the species. 
Asaphus romingeri and A. wisconsensis were described by Walcott 
without illustration, but are represented by a considerable number of 
fragmentary specimens in the Walcott collection of the M. C. Z. 
Two imperfect cranidia from the Black River at Russia, Herkimer 
county, N. Y., have attached to them original labels indicating that 
they are the types of the two species. These labels have, however, 
