256 



NEREIDES. 



tion into the Heteronereicl condition of the Neapolitan Nereids, in 1870, groups the 

 bristles of the Nereids into two divisions : 



(1) Heterogomph bristles in which the distal end of the shaft is prolonged in a point, 

 so that an oblique articulation takes place. 



Fig. 62 a and b. — Homo- and heterogomph bristles of Nereis pelagica. 



(2) Homogomph, in which the distal end of the shaft forms a kind of sheath 

 for the terminal piece ; but the fact that in the ventral division of such forms as 

 Nereis pelagica, L., and Nereis cultrifera, Grube, a gradual transition from the former to 

 the latter occurs, shows that the distinction is artificial. He places some weight on the 

 distribution of the various bristles (four kinds) in the foot. He further describes two 

 canals in the maxillae of the Nereids in communication with the base, and opening 

 between the first two (distal) teeth, that is, the tip and the first tooth. In the heteronereid 

 of Nereis Dumerilii he found the cavity of each maxilla occupied by a peculiar proto- 

 plasmic tissue with nuclei, but whether the reticulated tissue secreted poison he 

 could not say. On the whole the beautiful drawings and the numerous observations by 

 Claparede on the Nereids in the two works just noticed make an epoch in their history. 



Grube, 1 in 1873, entered into an elaborate review of the characters upon which he 

 based the classification of the Nereidae, these being chiefly the armature of the proboscis 

 and the structure of the feet. His main divisions are as follows : 



A. Foot with two bristle-bundles, but not fissured accordingly. 



Lycastis, Sav. The foot is not split into tongue-like processes. It has small 



lobes with the bristle-bundles. Proboscis without paragnathi. 

 Foot divided into a dorsal and a ventral division. 

 The dorsal cirrus simple. 



Nereis, L. s. str., Aud. & Edw. The border of the foot split into three tongues, 

 the upper and middle pertaining to the dorsal, the ventral to the ventra 

 division. 

 Proboscis with paragnathi, seldom with soft papillae. 



1 ' Scliles. Gesell. f. v. Cultur/ Dec. 19th, 1873, p. 13 



B. 

 B 1 . 



