302 Rev. R. T. Lowe on Melampus, &c. 
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; yiz. 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, Tas. XIII. f. 13, 14, 15, 16, 17, 
(18 testa. var. (3.) 
Trunc. testa subpellucidd, solitiusculd; anfractibus plus minus - 
transverse striatis. 
Long. (in adulta) 2-3 lin.; lat. 1}. Anfr. 4. 
Cyclostoma truncatulum, Drap., p, 40, no. 17. Lam., VI., 2, p. 149. 
Helix subcylindrica, Mont., Test. Brit., p. 393, no. 17. 
a levigata; testd corneo-lutescente, levigatd ; striis obsoletis, vel ad 
suturas tantim conspicuis. 
Truncatella levigata, Risso, Hist. IV., p. 125, no, 300, f. 53. 
Cyclostoma truncatulum v.s Drap., loc. cit. t. 1, f. 31. 
B costulata; testd carnea; anfractibus costulatis, costellis crebris 
equidistantibus flecuosis subobliquis distinctissimis. Tax. XIII. 
f, 13—18. 
Truncatella costulata, Risso, Hist. IV. p. 125, no. 301, f. 57. 
Cyclostoma truncatulum, a & (3, Drap., loc, cit. t. 1, f. 28, 29, 30. 
Testa junior [3. 
Paludina Desnayersii, Payraud., Catal. p. 116, no. 245, t. 5, f, 21, 22. 
* Yet in another similar instance, one of them, Melampus equalis, and the 
undoubtedly aquatic Littorina vulgaris, did, after a confinement of about the 
same length. See Experiment 4, above, 
