302 Rev. R. T. Lowe on Melampus, SfC. 



is one of the marine Pectinibranchia : and what is equally satisfactory, 

 greatly strengthens the same conclusion respecting Melampus. And were 

 this conclusion less definitely proved in the present instance than it really is 

 by this Experiment 17, it would not be affected by the fact, that the same 

 individual was able to exist in atmospheric air, as above related (Experi- 

 ment 16), for nearly five weeks. For although this might well happen 

 to an aquatic animal shut up in a close box with other aquatic species, 

 even when the others did not survive,* still, I apprehend, the converse 

 cannot hold; viz. that an atmospheric air-breathing Molluscous animal 

 could exist a fortnight, or even much more than twenty-four hours, 

 immersed in sea-water. However, this Truncatella really lived fourteen 

 weeks so immersed. 



SPECIERUM CONSPECTUS. 



1. Truncatella Truncatula, Tab. XIII. f. 13, 14, 15, 16, 17, 

 (18 testa. var./3.) 

 Trunc. testd subpellucidd, solidiusculd ; anfractibus plus minus 



transverse striatis. 



Long, (inadulta) 2-3 lin.; lat. l^. Anfr. 4. 



Cydostoma iruncatulum, Drap., p, 40, no. 17. Lam., VI., 2, p. 149. 



Helix subcylindrica, Mont., Test. Brit., p. 393, no. 17. 



(I laevigata; testd corneo-lutescente, Icevigatd ; striis obsoletis, vel ad 

 suturas tantiim conspicuis. 



Truncatella Icevigata, Risso, Hist. IV., p. 125, no. 300, f. 53. 



Cydostoma truncatulum y., Drap., loc. cit. 1. 1, f. 31. 



/3 costulata ; testd carnea; anfractibus costulatis, costellis crebris 

 tBquidistantibus jlexuosis subobliquis distinctissimis. Tab. XIII. 

 f. 13— 18. 



Truncatella costulata, Risso, Hist. IV. p. 125, no. 301, f. 57. 



Cydostoma truncatulum, a & /3, Drap., loc, cit. t. 1, f. 28, 29, 30. 



Testa junior (o. 



Paludina Desnayersii, Payraud., Catal. p. 1 16, no. 245, t. 5, f, 21, 22. 



* Yet in another similar instance, one of them, Melampus mqualis, and the 

 undoubtedly aquatic Littorina vulgaris, did, after a confinement of about the 

 same length. See Experiment 4, above. 



