We have not adverted to Malleus Anatinus of Chemnitz, because the figure of that shell is ambiguous. There is a remote resemblance in the lateral appendages of the beaks, but in other particulars the resemblance is less obvious, the body is sometimes curved as in the shell before us and sometimes straight, but the edges of the valves are parallel, and the shell itself pellucid: the figure in Chemnitz is less than half the size of our shell. This inhabits the seas of Timor and the Nicobar Islands. It should be observed in conclusion that there is a specimen of our species among the Hammer Shells in the British Museum, the _habitat_ of which is indicated by the word “Amboina:” it is much smaller than our shell. Besides this we have lately seen another example from New Holland, of a growth still larger than the shell we have delineated. We have entered thus minutely into the analogies of this shell from an apprehension we might otherwise in this instance submit as a new species an object that had been previously described. The result of our enquiry will tend to shew that if the species has not remained entirely unnoticed, it has never been described with much precision. ----- Footnote 22: Testa extus intusque nigra: lobo basis longiusculo. _Animaux sans vertèbres. T. 6. p. 145._ Footnote 23: Var. testâ albidâ; lobo basis abbreviato. _Ibid._ ------------------------------------------------------------------------ [Illustration: _29_ _London. Published by E. Donovan & Mess.^{rs} Simpkin & Marshall, Jan.^y 1, 1823._ ] ------------------------------------------------------------------------ ENTOMOLOGY. PLATE XXIX. PAPILIO TROS TROS’S BUTTERFLY. LEPIDOPTERA. GENERIC CHARACTER. Antennæ thicker towards the tip, and generally terminating in a knob: wings erect when at rest. Fly by day. * EQUITES TROJANI. SPECIFIC CHARACTER AND SYNONYMS. Wings indented, tailed, above and beneath black; on the anterior wings an abbreviated white band: posterior ones with sanguineous spots. PAPILIO TROS: alis dentato caudatis concoloribus nigris: anticis fascia abbreviata alba, posticis sanguinea maculari. _Fabr. Ent. Syst. T. 3. p. 1. 10. 30._ _Jon. fig. pict. 1. tab. 23._ * * * * *