94 EUROPEAN NEMERTEANS. 



cinia, embraces forms which are perhaps not so closely 

 related to each other as are all the Schizonemertini^ 

 with which they were amalgamated in Max Schultze's sub- 

 division of the E no pi a, but on the other hand they are 

 all of them as decidedly different from these as they are 

 from the Hoplonemei'tini. Whereas Cephalotrix and 

 Carinella must be looked upon as Nemerteans in which 

 a more primitive stage of differentiation is retained (ner- 

 vous system , proboscis , genital chambers) , Valencinia 

 and Folia represent types which have already be- 

 come further developed and of these Folia seems to ap- 

 proach , by certain well-marked characteristics , to the" 

 Hoplonemertini. Of these characters I must mention 

 one in particular : the curious, comb-like arrangement of the 

 numerous small grooves in the epidermoidal tissues of the 

 head, which together constitute the system of respiratory 

 furrows. The ciliated respiratory duct, leading into the 

 nervous tissue (vide: Zur Anatomie und Physiologie des 

 Nervensystems der Nemertinen , by the author of this pa- 

 per in: Verhandelingen van de Koninkl. Akademie van 

 Wetenschappen, Vol. XX, Amsterdam 1880) does not 

 communicate with the exterior by a simple circular opening 

 — as it does in Valencinia — nor does it open at the 

 bottom of a deep, longitudinal and richly ciliated furrow 

 (as in the S c h i z o n e m e rtini), but it terminates exteriorly in 

 a transverse groove , which encircles the head , with the 

 exception of a small interruption in the median line of 

 the dorsum. Numerous short grooves, all directed to- 

 wards the anterior extremity of the animal , take their 

 origin from this transverse furrow and are quite as strongly 

 ciliated. The same arrangement occurs in the two highly 

 differentiated genera of armed Nemerteans: Amphiporm 

 and Drepanophorus, which in so many respects are however 

 entirely different from Folia and all other Falaeonemertini. 

 In Folia curia (young specimen) I counted about sixty, in Folia 

 minor twenty-four of these secondary grooves. In no other ge- 

 nus of Palaeonemei-teans I could as yet observe a similar arran- 



Notes Iroiii tlie Leyden ^liiseum. Vol. II. 



