No. 12. — Reports on the Results of Dredging, under the Supervision 
of ALEXANDER AGASSIZ, along the East Coast of the United States, 
during the Summer of 1880, by the U. S. Coast Survey Steamer 
* Blake,’ COMMANDER J. R. BARTLETT, U. S. N., Commanding 
(Published by permission of CARLILE P. PATTERSON, Supt. U. S. Coast and 
Geodetie Survey.) 
XIII. 
Report on the Pycnogonida, by Ebmunb B. WILSON. 
Tum specimens described in the following pages were dredged by Mr. 
Agassiz, during the summer of 1880, off the eastern coast of the United 
States, in a region extending from South Carolina to the northeastern 
extremity of St. George's Banks, lying between N. Lat. 31° 57! and 
41? 35', and W. Long. 78? 18' and 65? 35'; the range of depth was 
from 73 to 1242 fathoms. 
It was at first intended to include descriptions of the Pycnogonida in 
the report on the Crustacea from the same region, which is in course of 
preparation by Professor Smith, of Yale College. Upon examination, 
however, the collection was found to possess features of considerable in- 
terest ; and, though the species are few, they seem to merit independent 
description and illustration. The most striking feature of the collection 
is the remarkable size of most of the forms, which may fairly be called 
colossal in comparison with shallow-water or littoral species. Of the 
three species of Colossendeis (two of which are apparently undescribed) 
the smallest has a span of 14 cm, between the tips of its outstretched 
legs, while the largest has an extent four times as great. The new 
genus Sceorhynchus has an extent of more than 19 cm., —a gigantic 
size as compared with the dimensions of its nearest allies. The most 
abundant species of Nymphon is the largest of that extensive genus; 
and one species of the new genus Pallenopsis is more than twice as large 
as any of the species of allied genera (Pallene, Phoxichilidium, Anoplo- 
dactylus), which are known only from the littoral zone or comparatively 
shallow water. 
Tt is, further, interesting to note that in a number of forms the visual 
VOL. VIII. — NO. 12. 
