798 PROCEEDINGS OF THE ACADEMY OF [DeC, 



and mediissc and other constituents of that strictly pelagic fauna. 

 Though this locality is not strictly within the limits of the Woods Hole 

 region it is frequently visited by expeditions sent out from Woods 

 Hole by the U. S. Fish Commission, and members of its fauna are 

 every summer carried into Mneyard Sound by favoral^le winds. 



The discovery of a species of Drieschia in oin- waters is of exceptional 

 interest, as the type and hitherto onl}^ known species of the genus was 

 described by Michaelsen''' from the neighborhood of Ceylon, and has not 

 been found since. Like the new species, it is pelagic and pellucid, but 

 differs decidedly in specific characters. D. pelagica has 28 somites and 

 13 pairs of elytra; the palpi are as long as the tentacular cirri and 2^ 

 times the antennse; the dorsal cirri are all alike and have very thick 

 but short ovate ceratophores, and the stout setse are strongly curved 

 and of a quite different shape. The elytra have the same peculiar 

 inflated character tlescribed for D. j)eUucida, though apparently less 

 pronounced. 



Tomopteris helgolandica Greef. ? 



Several specimens of a perfectly limpid si)ecies of Tomopteris were 

 taken in the tow-net, lowered nearly to the bottom in 17 fathoms, at 

 Crab Ledge, east of Chatham, Massachusetts, on August 19, and again 

 on August 22, 1902. The same species was also taken at the surface 

 at Woods Hole in July, 1903. Prof. Verrill has recorded the occur- 

 rence of the young of Tomopteris in Vineyard Sound," and an unidenti- 

 fied species of the genus from the Gulf Stream material collected b}- the 

 Albatross in 1883.^ These appear to be the only published records of 

 the capture of this interesting annelid in this region. Miss Katharine 

 Bush has kindly compared one of my specimens with those from the 

 Gulf Stream in the Yale Museum, and states that they are of the same 

 species, a conclusion which I am enabled to confirm througli Prof. 

 Verrill's courtesy in sending to me an unpublished drawing of his 

 species. 



After a careful examination of the very considerable literature of 

 the genus I am still in doubt concerning the identity of the Massachu- 

 setts examples. Notwithstanding Apstein's excellent monographic 

 work,^ there are still wanted careful descriptions of the changes under- 

 gone by many of the species during growth and of the very considerable 

 variations which occur among the mature worms, of the limits of which 



^ Mitteilungen Naturhis. Mus. Hamburg, IX (1891), p. 6. 

 ^ Invertebrates of Vineyard Sound, p. 332 (626). 

 ' Rep. U. S. Fish Commission for 1883 (1885), p. .594. 

 ^ Alciopiden und Tomopteriden der Plankton Expedition. 



