On the Auditory and Olfactory Oryans of Spider <i. 329 ITab. Seychelles Islands [Dr. E. Perceval WriyJit). The nearest ally of this species is C. fusiforniis, Reeve, from which it may be distinguished Ly the sliarper angulation of the whorls, more attenuated body-whorl, tiner liration on the columella, and the slightly longer spire. The slight sinus towards the lower part of the labrum is comparatively con-spicuous. XL. — T/ic Auditory and Olfactory Organs of Spiders. By Friedrich Dahl*. [Plate XII.] Last year I published, in the ' Zoologischer Anzeiger ' (p. 267), a short communication upon some peculiarly articu-lated hairs in the Arachnida, which I interpreted as an organ of hearing. I have since continued my investigations upon this subject, as also upon the sense-organs of the spiders in general, and venture here to make known some further results. In the first place I ascertained that the spiders have not only auditory but also olfactory perceptions, and after long seeking I succeeded in discovering in the maxillffi an exceed-ingly peculiar organ which, for reasons presently to be given, I think may be regarded as the olfactory organ. But before proceeding to its description I would make some additions to the exposition of both the histological structure and the systematic significance of the auditory hairs, and also replace the indifferent woodcut representations with better drawings. As I have already mentioned in the above-mentioned article, the auditory hairs occur upon the upper surface of the legs and palpi. I also indicated that with reference to these hairs our indigenous spiders may be divided into two groups. I have since examined, in connexion with this, nearly all the spiders that were at my disposal in a suitable state, and I can not only sustain the assertion then made, but can also make some further remarks upon the classification of the Spiders by the employment of this character. The first group, which has been already separated upon other characters from the other spiders, 1 characterized as follows : — * Translated bv W. S. Dallas, F.L.S., from the ' Archiv fiir inikro-ekopische Anatomie,' Band xxiv. pp. 1-10.
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