358 ZOOLOGY. 



as to leave even its relationshix) a matter of discussion. G. O. Sars (lis. 

 tiuguishes it as a group (Telobrauchiata) of the Opisthobrancliiates, 

 co-ordinate with the Tectibranchiata and Nudibrauchiata. H, von 

 Ihering differentiates it as a class of "Vermes — Phylum Amphineura," 

 the Chitons forming another class. E. Eay Lankester isolates it still 

 further, considering it as representing not only a class (Scolecomorphal 

 but a primary group (Lipoglossa) of MoUusks having no affinity to the 

 Chitons. A new form of this grouj), exhibiting characters, too, deemed 

 wanting in the type, must be of unusual interest. Such is the species 

 made known as Proneomenia tSJuiteri* Like Neomenia, Froneomenia is 

 worm-like and subcylindrical, but unlike that form it is provided with a 

 distinct though small radula. Two specimens of the species were 

 dredged by Dr. Sluiter in the Barent Sea. 



REGENERATION OF PARTS IN GASTROPODS. 



Long ago Spallanzari and afterwards Schiiffer experimented upon the 

 regeneration of parts in snails, but this subject has since been much 

 neglected. Recently Mr. Justus Carriere has reinvestigated the ques- 

 tion t, and has found, like his predecessors, that the tentacles, with the 

 eyes and the labial processes in the gastropods, can be comi)letely 

 regenerated. On the other hand, when the pharynx or supra-oesopha- 

 geal ganglion is cut out death ensues. Mr. Carriere took all precau- 

 tions in his investigations, and all the conditions to insure accuracy 

 Avere fulfilled, that is, with respect to the health of the animal, the 

 parts removed, &c., for a different result would ensue if the animal was 

 taken when its energy was concentrated in the formation of generative 

 products, and it was therefore found that a season of rest, as at the 

 begiuning of summer, or the autumn season, was the most satisfactory 

 time. The individuals experimented upon represented common Euro- 

 pean species of Helix. Those that gave the most satisfactory result 

 were Helix nemoralis and H. hortensis; H. pomatia was more sensitive, 

 and H. arhustarum and H. fruticum the least capable of rei>roduction of 

 parts. 



In the case of the eye it was ascertained thflt the method of regener- 

 ation was analogous to that of the first formation of the organ. There 

 was an invagination of the epithelium, the formation of a closed vesicle, 

 and the primitive cylindrical cells became partly converted into corneal 

 (jells, and i)artly into rods and cones. The time reipiired for this re- 

 generation was fifty or sixty days. 



Experiments were also instituted with respect to the aquatic pulmon- 

 ates, but the results were less satisfactory on account of their liability 

 to attack by fungus in the wounds. 



*Hn))reclit (A. A. W. )• Proneomenia SluUeri gexi. et sp. u., eine neue arcliaische Mol- 

 Inskciiforra aiifj dein Eisraecr. Zool. Avzeh/er, iii Jalirg., pp. 589-590, 29 Nov., 18S0. 



t Carriere (J.). Ueber die Regeneration bei deu Laud-Pulmonateu. Tayhlatt der 52 

 Vers, dcutsch. Xuturf., pp. 225, 22(3. 1879. 



