A. E. Verrill on New England Nudibranchiata. 405 
hydrogen line, near G, by opening the slit of the spectroscope 
and attaching a small camera to its eye-piece. As a picture of 
course it amounts to ve ry little. It required an exposure o 
three minutes and a half, and the polar axis of the telescope 
being imperfectly adjusted, the clock-work failed to follow per- 
fectly, so that no detail is visible, and the picture will not bear 
much magnifying. I am convinced, however, that by using a 
more sensitive collodion, and taking proper pains with the ad- 
justment of the in strument, satisfactory photographs of these 
curious objects may be obtai ined. 
I may add that the spectroscope employed has the > dispersive 
power of 13 prisms of flint, each with an angle of 55° 
Rie it I observed this afternoon i in ee spectrum of a spot, 
e reversal as the eee a 1; De, D;, 1474 K, 
ree faint), 04, by, bs, &, F, 279 K, (ih, pers ‘h (Ha). bs was 
most conspicuous after C,, Ds, and B 
ART. XLVL—Oboniributions to Zoilogy from the Museum of Yale 
College. No. 8.—Deseriptions of some New England Nudibran- 
chiata; by A. E. VERMILL. 
Durine a dredging expedition to obec ek Me., and Grand 
Menan, the past season, in company wi Oscar "Harger and 
PEE Dwinelle, students in the Sheffield Scientific School, the 
following very interesting species was obtained. Many ihe 
Nudibranchs were cae observed, most of which are well known 
species 
Dendronotus robustus, sp. nov. Figure 1 
Body stout, about 2 inches long; 5 broad, ca about the 
Po m height, — quadrangular, tapering Bonet 
but much less e than in D. arborescens, as we h 
stouter, eitongiauie Y fede in about six pairs, those of the 
e first pairs with a sup ee gee one of nearly the same 
eis saa separately outside of, but close to their bases ; on 
the fourth pair these originate te from the base as large branch 
rane are diffusely arborescent and very much subdivided, 
the divisions pene P e very rapidly, the branches being 
more equal ore sp. 1 than * 
and do not pe the a , slender and acute ches seen 
in that s : Oe ant ts ieee 
ae and stout, about 4 of an inch long and 12 eter, 
a five sans, ‘round, smooth, tapering, ac acute pepe of 
which the two posterior ones are longest. The tentacles (figure 
