THE GENERA OF NEMERTEANS. 199 



abnormally severed by an oyster, into the opened shell 

 of which it was stealthily tr3dng to penetrate. The extreme 

 rarity of the species was a corro berating evidence. On 

 these grounds I propose to cancel the generic name of 

 Lohilahrum, the type ^) of which probably belonged to 

 one of the species of Atlantic Lineidae. 



The remaining genera mentioned by these three promi- 

 nent authors (even when a few of them may presently 

 be shown to be synonymous, and their number therefore 

 liable to further reduction) must form the nucleus for any 

 further proposal for the systematic arrangement of the 

 order. Before developing my own views on this head I 

 have still to account for several of the genera which are 

 contained in the list on page 194. Planaria and Gordius 

 have come to be used for different types of worms and 

 the Nemerteans described under these generic names must 

 be distributed under the head of Cerehratulus and Lineus. 

 Tuhulanus will be shown to be identical with Carinella ; 

 Meckelia was used for the same worm which had served 

 as the type to Renier's Cerehratulus marginatus , so was 

 Serpentaria and both of them must be again substituted 

 by the name which has the indisputed claims of priority. 

 Mac Intosh applied the name Meckelia to quite a different 

 animal which seems to be misplaced among the Lineidae 

 and may prove to be more closely related to the Cephalo- 

 tricidae or Valenciniaidae , at all events to belong to the 

 suborder of Palaeonemertini (vide p. 206). Notospermus and 

 Notogymnus were established upon an unmistakable Cere- 

 hratulus as Quatrefages has long ago shown. Siphonenteron 

 and Vermindus have never been well characterized ; the former 

 was moreover synonymous with another genus of the same 

 author from the beginning, and so both have been aban- 

 doned. Then again Astemma and Cephalotrix are synonyms 

 and with Mac Intosh we propose to retain only the latter 



1) I inquired for the type specimen at the Museum in the Jardin des 

 Plantes; however is was not to be found, and probably has never reached Paris. 



Notes from the Leyden IMuseum. 



