No. 1.— A NEW PTEROPOD FROM NEW ENGLAND.^ 
BY C. H. DANFORTH. 
Introductory Note. 
Three pteropods have been found in Casco Bay, Maine. The first 
noted was Clione borealis, reported on by C. B. Fuller on April 6, 1868, 
and more fully by Dr. William Wood ('69). The second species was 
Spirialis gouldii which was found in considerable abundance in the 
plankton at the Harpswell laboratory on the evening of August 23, 
1901. This species was described by Stimpson ('51) as coming from 
"the whole coast of New England." It has been recorded by Mr. 
Alexander Agassiz from Nahant (north of Cape Cod) and Naushon 
(south of Cape Cod), Massachusetts; by Verrill and Smith from the 
Georges Banks and from No Man's Land (Massachusetts) ; and from 
Newport, Rhode Island, by J. W. Fewkes. It did not occur in our 
Harpswell collections on the 22d or on the 24th of August. On the 
22d the wind was strong from the northward and continued from 
that direction for twenty-four hours, so the specimens could not have 
been drifted in by the wind. 
The third species is that which forms the basis of the following paper. 
It occurred in the plankton on the nights of August 28 and September 
5, 6, 7, and 8, 1902, and on one or two nights following. On a hasty 
examination it was regarded as a larva of some gymnosomatous 
pteropod, and as Clione had been taken at Portland, about a dozen 
miles away, it was thought that it was possibly the young of that form. 
All of these last specimens were narcotized with chloral hydrate, 
killed and hardened with corrosive acetic, and finally preserved in 
alcohol. Later some of them were sectioned, chiefly with a view to 
seeing their histological condition. To my great surprise they Avere 
found to be not larvae but sexually mature adults. The gonads con- 
tained well formed eggs while in the testicular area all stages of sperm- 
atogenesis were visible and in some specimens the genital ducts were 
filled with perfectly formed spermatozoa. The whole material was 
then turned over to my pupil, Mr. Danforth, for study, the result being 
the present paper. 
* Contributions from tlie Biological laboratories of Tufts college. No. 46. 
