Hurrox.—On Rhachiglossate Mollusca. 217 
reference, and partly because it was thought desirable that the original 
descriptions should be reproduced in a form that was easily attainable 
throughout the colony. The present paper is an attempt, for a portion of 
the Mollusca, to clear the list of the names of species not found in New 
Zealand, and to settle, to some extent, the true nomenclature of those that 
remain. 
The number of shells erroneously put down to New Zealand is sur- 
prising. Thus the present list contains 45 true New Zealand species, while 
87 have been rejected as spurious. Mr. Tenison-Woods is inclined to 
think that this is in large part owing to the late Mr. L. Reeve regarding 
Van Diemen's Land as a part of New Zealand. This is probably true, but 
I suspect that most of the mistakes must be attributed to the carelessness 
of Mr. Cuming, who appears to have attached localities to his shells pretty 
well at random. 
The classification followed is that of Professor Theodore Gill, of Wash- 
ington, which I regard as, on the whole, the most natural yet proposed. 
Many conchologists object to it as founded too much on lingual dentition, 
‘which they say is inconvenient ; is not found in the whole of the Mollusca ; 
fails to separate even the phytophagous from the zoophagous animals; is as 
yet known only in a comparatively few species ; and cannot be applied to 
fossils. But the odontophore is the most complicated organ possessed by 
the Gastropoda, and therefore is, of all others, best adapted for tracing out 
genealogies; for it is impossible to believe that two similar complicated 
dentitions could have arisen independently. On the other hand the shell is 
simple in structure; and very similar shells have certainly arisen indepen- 
dently in several cases. The objection that an examination of the dentition 
is “inconvenient” is of no value; conchologists must learn to use the micro- 
scope like other naturalists. To object to the Gastropoda being classified by 
the odontophore because it is absent in a few genera is ridiculous. That it 
fails to separate the phytophagous and zoophagous species is only partly 
true ; but, so far as it goes, shows that such a division has but little value. 
That the dentition is as yet only known in comparatively few species is 
because conchologists will not take the trouble to examine it, and merely 
proves how much yet remains to be done in the classification of the Mol- 
lusca. The last objection, that the test cannot be applied to fossil species, 
is hardly worth answering. It is as if paleontologists were to insist upon 
botanists classifying plants by their leaves because flowers were rarely 
found fossil. To object to an attempt to find a true classification of living 
Mollusca because, if found, it might upset our ideas of the value of shells in 
paleontology is, I suppose, one of the weakest arguments ever uttered by 
naturalists. 
