344 THE ANNELIDA POLYCHAETA. 



ventral in position. The glands seem to be toxic to certain organisms preyed 

 upon. 



It is now established that epitoky occurs in this family, certain forms, at 

 least, acquiring at the time of sexual maturity long, natatory, notopodial setae 

 similar to those acquired in various other epitokous forms, the parapodia 

 elongating at the same time. Also with the development of the sexual products 

 the musculature undergoes reduction, the proboscis degenerates, and its jaws 

 may become detached and disappear. At this period of sexual maturity the 

 animals, of course, become pelagic, as is so frequently the case in other forms of 

 similar mode of Ufe.' A very interesting case of epitoky occurs in the new 



genus Telake (p. 345). 



The glycerids frequent especially sandy mud at moderate depths. Some- 

 times they are cast up on the shore at beaches, and also at times are found under 

 stones and in the fissures of rocks between tide-marks. They have been ckedged 

 mostly at depths ranging from three or four to a hundred fathoms. Glycera 

 capitata Oersted was dredged by the Porcupine at 664 fathoms ; and the Alba- 

 tross dredged Hemipodus mexicanus, sp. nov., at 628 fathoms, Glycera pro- 

 fundi, sp. nov., at 859 fathoms; while G. brachiopoda Moore has been taken at 

 from 222 to 1,400 fathoms. These cases, however, are exceptional. 



Many of the glycerids are active animals which progress through the water 

 mth a screw-like motion, probaljly much the same as that they execute in moving 

 in wet sand. In burrowing in the sand they are seen to apply the snout to the 

 surface, then thrusting out the proboscis forcibly and rapidly, and moving step 

 by step into the successive depressions thus made, in the same manner as occurs 

 in Nepthys. 



Key to Genera. 



a. Body of the pelagic form presenting two shari:)ly distinct regions, in tlie posterior of which only 



simple setae occur Telake, gen. nov. 



aa. No such division with parapodia of posterior region bearing only simple setae. 



b. Parapodia uniramous Hemipodvs Quatrefages. 



6b. Parapodia biramous. 



c. Proboscis short; supporting piece of maxilla rod-shaped Glycerella Arwidsson. 



cc. Proboscis long; supporting piece of maxilla triangular or bifurcate. 



d. Proboscis without hard, dentate processes among softer papillae Glycera Savigny. 



dd. Proboscis with numerous toothed or hooked pieces among softer papillae. 



Hemiglycera Ehlers. 



Synonyrny of Genera. 



Kinberg (Ofvers. K. vet. akad. Forh., 1865, no. 4, p. 245) transcribes the 



"Hemipode" used by Quatrefages in his note on Classification of annelids in 



' Cf. Arwidsson, Bih. K. svenska vet. akad. Handb., 1897, 23, no. G, p. 30. Also Gravier, Nouv. 

 arch. Mus. hist, nat., 1906, ser. 4,^8, p. 135. 



