204 



name for Scissurella crispata, I have no objection to the adoption of 

 Anatoma, provided it be spelled properly, and not attributed to 

 Montfort.- 



3. Note on Cyclostoma articulatum. By S. P. Wood- 

 ward, F.G.S. Communicated by Prof. Owen. 



(Mollusca, PI. XLVI.) 



This land-snail is peculiar to the Island of Rodriguez, and belongs 

 to the subgenus Tropidophora (Troschel), characteristic of the 

 Mascarene Islands. Numerous examples were collected in February 

 1858 by the late Madame Ida Pfeiffer, who conveyed them to the 

 Mauritius, where they continued active, but took no food during a 

 stay of two months. Three individuals remained alive after the 

 voyage to England, which occupied ten weeks, and several others 

 were sufficiently preserved for examination. They were brought 

 over packed in paper and rags, in a tin pot with a lid, and were not 

 taken out until a fortnight after their arrival. One of these snails 

 lived for some months under a bell-glass with moss and ferns, and 

 afforded frequent opportunities for examination. The animal was 

 of a pale buff colour, with darker tentacles and muzzle ; the tentacles 

 were acute, rugose, and slightly annulated ; the muzzle annulated, 

 grooved beneath, and bilobed at the end, which was constantly used 

 in walking. The foot was ample, with a deep central groove dividing 

 it into two lateral elements moved alternately in walking. When it 

 retired and closed its shell, it still adhered, and sometimes became 

 suspended, by a tenacious thread of mucus. 



Madame Pfeiffer also brought home specimens of Cyclostoma ca- 

 rinatum and C. (Otopoma) listeri, from Mauritius, which were in a 

 tolerably fresh state. The lingual dentition of these species differs 

 slightly from that of C. articulatum. 



EXPLANATION OF PLATE XLVI. 



» Figs. 1-7. Scissurella elegans : several varieties at different periods of growth, 

 magnified 24 diameters. 

 1, 2. Young shells, exhibiting the commencement and successive filling 

 up of the slit. 



3-6. Old examples, showing the extent to which the shell grows after 



the establishment of the foramen. 

 7. Front view of a shell with the multispiral operculum. 

 Fig. 8. Scissurella mantelli, magnified 40 diameters. 



Fig. 9. Scissurella (Anatoma) crispata, magnified six times. From the coast 



of Norway. In the collection of Mr. MacAndrew. 

 Figs. 10, 11. Cyclostoma articulatum, of the size of life. — June 9, 1858. 

 Fig. 12, Its lingual ribbon, natural size. 

 Fig. 13. A portion of the same, magnified. 



