124 BULLETIN OF THE BUREAU OF FISHERIES. 



and all of the Oligochaeta so far as listed. As has already been stated, it is likely that 

 most of the benthic species extend nearly or quite up to the littoral zone; and indeed 

 they often occupy the latter as well. 



On the other hand, many of our local Annulata are pelagic during a part, at least, of 

 their existence. This is true of the larvae of nearly all the Polychaeta, and holds for the 

 sexual phase of many adult worms, particularly the Syllidae and Nereidae. One highly 

 modified and typically pelagic form, Tomopteris helgolandica, is taken in the local tow 

 during the winter and spring, sometimes occurring in abundance. Two exotic species, 

 which may perhaps be termed pelagic, were found upon floating timbers among goose 

 barnacles. These are Amphinome pallasii a and Hipponoe gaudichaudi. 



A few of the more striking examples of a difference of habitat being shown by 

 different members of the same genus are as follows: 



Nephthys. 



N. incisa: Frequents bottoms of soft mud. 



N. bucera: Frequents sandy bottoms. 

 Nereis. 



N. pelagica: Clear waters, non-muddy bottoms. 



N. limbata: Strictly littoral, preferring foul and brackish waters. 



N. virens: Diverse habitat. 

 Cirratulus. 



C. grandis: Shores and deeper waters in sand and gravel. 



C. parvus: Deeper waters only, in colonies of Amaroucium pellucidum. 

 Amphitrite. 



A. ornata: Inner waters of region, strictly littoral. 



A. brunnea and A. cirrata: Only recorded from Crab Ledge. 

 Pista. 



P. palmata: Said to frequent purer waters and cleaner sand than P. intermedia. 

 Spirorbis. 



S. spirorbis: On rock-weed, littoral. 



S. tubaeformis: On Phyllophora and Chondrus, from adlittoral zone to greatest depths of region. 



S. quadrangularis: At Crab Ledge only. 



S. stimpsoni: At Crab Ledge only. 



S. fewkesi : From algae in deeper waters of Vineyard Sound. 



The following species of Annulata were taken during the dredging operations of the 

 Survey: 



Autolytus ornatus. 



Eusyllis fragilis. 



Odontosyllis lucifera. 



Paedophylax dispar. 



Syllis pallida. 



Trypanosyllis sp. 

 *Eulalia annulata (chart 54). 



Eulalia gracilis. 



Eulalia pistacia. 



Eumidia americana. 



Phyllodoce catenula. 



Eunoe oerstedi. 

 *Harmothoe imbricata (chart 55). 

 *Lepidonotus squamatus (chart 56). 



Lepidonotus sublevis. 



Sigalion arenicola. 



Sthenelais gracilis. 



Sthenelais picta. 

 *Nephthys bucera (chart 57). 

 *Nephthys incisa (chart 58). 



Nereis arenaceodentata. 



Nereis dumerilii. 

 *Nereis pelagica (chart 59). 



Nereis virens. 

 *Platynereis megalops (chart 60). 

 *Marphysa leidyi (chart 61). 

 *Diopatra cuprea (chart 62). 



Nothria conchylegia. 

 * Arabella opalina (chart 63). 



Drilonereis longa. 



This, we learn, is known to be littoral in the West Indies. 



