On Natural and Artificial Section in some Chatopod Annelids. 323 



intus concava insuper anfractum penultimum antrorsum ascendente 



munito. 

 Diam, major 22-23, minor 17-19, axis 5-6 mill. 

 Habitat non procul ab urbe Moulmein. Invenit Col. R. Gordon. 



The last whorl is slightly solute behind the wing, which runs 

 forward up the penultimate whorl, to which it adheres. This is 

 the first species of the genus which has been discovered in Bur- 

 mah. Two specimens were found on the banks of the xlttaran 

 River, near limestone rocks, fifteen miles from its mouth. In 

 one shell the sutural spiracle is worn down to the surface. The 

 operculum was not obtained. 



Animal of Sophina. 



I am indebted to Col. R. Gordon for observations on the 

 animal of Sophina. It proves to be acrommatous, and allied to 

 Helix, from which, with reference to the anomalous slit in the 

 columella, it may be separated on grounds as decided as those 

 which suffice for the distinction of the genera Achatina and 

 Streptaxis. 



Sophina. — Animal with four tentacula, two long and two 

 short; the eyes situated on the summits of the larger pair. 

 Colour greyish-blue, with a yellow tint, and a dark spot between 

 the greyish-blue tentacula, the dark colour extending along the 

 neck. 



Cheltenham, April 6, 1863. 



XXXVI. — On Natural and Artificial Section in some Chatopod 

 Annelids. By W. C. Minor*. 



The circumstances of spontaneous fission have been observed in 

 80 few species of Annelids at present as to make every additional 

 observation of value, even though only confirmatory of what is 

 already known upon that subject. This consideration, and the 

 fact that all views of its nature in the Oligochaeta seem to be 

 based upon the observation of one species {Stylaria proboscidea), 

 have tempted me to publish the following brief investigations, 

 however they may want any very special novelty to give them value. 

 It is now nearly one hundred years since the distinguished 

 Danish naturalist. Otto Fr. Miiller, studied the phenomena of 

 spontaneous fission in the freshwater Naidsf; and his able little 



* From Silliman's American Journal for January 1863. 



t Trembley had discovered it long before this, as he observes in his 

 * Memoires p. s. a I'hist. d'un genre de Polj'pes d'eau douce,' 1 744 ; and 

 Roesel, in his * Insektenbelustigimgen,' describes the united parent and 

 bud ; but the former did no more than observe the fact, and the latter 

 wholly misunderstood what he saw. 



