Pim^LODOCIDAE. 99 



means of their probosces. He found in the digestive tube of Eulalia viridis 

 (Linne) another individual of the same species ahnost intact; and St. Joseph 

 made a similar observation in the case of Eulalia pallida Claparede. They 

 often attack forms larger than themselves. Rarely vegetable fragments, as of 

 Fucus, and diatoms are found in their alimentary tracts. 



Gregarines occur frequently in the alimentary tract of phyllodocids. A 

 number of external parasites have been noted by St. Joseph and others, e. g. 

 colonies of Vorticella on Anaitides mucosa (Oersted), the orthonectid Rhopalura 

 pterocirri on Sige (Pterocirrus Claparede) macroceros, a crustacean, Herpyllobius 

 articus, on Eulalia pallida, etc. 



In this work the groupings and general system elaborated by Bergstrora 

 in his recent revision (Zui* systematik der polychaetenfamilie der phyllodociden, 

 Zool. bidrag, 1914, 3, p. 37) have been in general adopted. 



Key to the Subfamilies and Genera. 



a. No composite setae present Natinae, subfam. nov. 



Setae of two distinct types; two pairs of tentacular cirri both belonging to the first somite; 



notocirri of first ordinary somite strongly developed Nans, gen. nov. 



aa. Composite setae present. 



b. Eyes present; notocirri of the normal foliaccous type; tentacular cirri present. 

 c. Notocirrus of first normal somite reduced; tentacular cirri either two pairs, both on the first 



somite, or three pairs with one on the first and two on the second somite Etconinae. 



d. With three pairs of tentacular cirri; ventral tentacular cirri of second somite foliaceous. 



Pseudomy slides Bergstrom. 

 dd. With but two pairs of tentacular cirri; all tentacular cirri filiform. 



e. The peristomium bearing distinct setigerous parapodia; pelagic forms. . . .Pelagobia Greef. 

 ee. Peristomium without setae or parapodial processes proper; non- pelagic or creeping forms. 

 /. First normal somite with setigerous parapodia. 



g. Proboscis distally with two lateral rows of true papillae and also bearing chitinous 



denticles Mysta Malmgren. 



gg. Proboscis smooth with neither true papillae nor denticles Eteone Savigny. 



//. First normal somite only with ventral cirri, parapodia proper and setae wholly lacking. 



Hypereteone Bergstrom. 

 cc. Notocirrus of first normal somite fully developed. 



d. With only two pairs of tentacular cirri, one on the first and one on the second somite which 



latter bears also an ordinary ventral cirrus Lugiinae. 



Lugia Quatrefages. 



dd. With more than two pairs of tentacular cirri, or rarely with but two pairs, in which case the 



second somite bears no neurocirrus. 



e. Three pairs of tentacular cirri or but two, of which only one pair occurs on somite I. 



/. Tentacular cirri occurring on but two somites and either three pairs with the two pairs 



on the second somite, or else but two pairs with ventral cirri of second somite absent 



or rudimentary Mystidinae. 



g. With three pairs of tentacular cirri, fully developed, two pairs pertaining to the second 



somite; prostomium free Mystides Thcel. 



gg. With only two pairs of developed tentacular cirri, or a rudimentary third pair may 

 be present (ventrals). 

 h. All setae composite; prostomium fused with the first soniite . Pedinosoma Reibisisch. 

 hh. Simple as well as composite setae present. 

 i. Prostomium fused only with the first somite. 



