388 Prof. De Brignoli and Prof. Morren on the 



such parts. The quantity of animal matter in the laminae 

 gives them an opalescent appearance. Tn structure, this fossil 

 resembles the Serpula compressa of Mm. Con., tab. 598. f. 3; 

 but it does not diminish so rapidly. Width ^ an inch. 



Nemertina, MacLeay. 



The Nemertina are white-blooded worms like some of the 

 Hirudina or Leeches. In this group, however, the character 

 of articulation becomes most indistinct. Rudolfi has placed 

 Gordius along with Nemertes (Ent. Syst. 572.); and if Gor- 

 dius goes into the group of Nemertina, it is possible that Fi- 

 laria may also. Nemertes Borlasii, is a long black sea-w^orm, 

 which is said to suck Testaceous Mollusca. The articulations 

 of its body become visible when it is contracted. If the long 

 vermiform impression in the Cambrian Rocks of Llampeter, 

 Murch. Sil. Syst. PI. 27. f. 4. belong to organic substances, 

 it can only be referred to some animal between Gordius and 

 Nemertes, although probably nearer the former genus. As 

 yet, however, Gordii are only known to occur in fresh water, 

 "whereas this fossil production, if it belong to the animal king- 

 dom, was evidently, like Nemertes, a native of the sea. 



Genus NEMERTITES? 



Animal marine, with the linear body, of a Gordius or Fi- 

 laria. 



Spec. 1. Nemertites Ollivantii. Murch. n.s. PI. 27. f. 4. 



XLVII. — Notes on the Excitability and Movemevtt of the Leaves 

 in the Species of Oxalis. By Professor J. De Brignoli 

 DE Brunhoff of Modena, and Prof. Morren of Liege. 



In the Bulletin of the Royal Academy of Brussels for last 

 July, an extract is given by M. Morren, of a letter received by 

 him from Prof, de Brignoli of Modena, of the 23rd of May 

 1839, containing some interesting details relative to the exci- 

 tability and spontaneous movement of the leaves of Oxalis 

 stricta, which had been accidentally observed by tw^o of his 

 pupils, one of whom had casually, whilst engaged in conver- 

 sation, been striking them with a small cane among the plants 

 that grew wild under the trees in the public garden. 



