Io6 SVKES : MAI.ACOLOGICAL NOTES. 



Cijdutus (ji<janteu^, Gray, xa.x. fi--<rlieri, Hidalgo: iNliller, Malak. 

 Rlatt , 1879, N.F., Bd. i, p. 140. 



III. Aperostoma eonfusum, n. ?p. 



(PI. X, fig. 2.) 



Cijclo^forna (li(ja)tteuri}, Gray : Pfeiffer, Conch. Cab., Cyclo.stomacea 

 [1846], p. ii, pi. i, figs. II — 14. 



The first reference I can trace is that of Reeve (Conch. Syst.) 

 which appears to have really appeared 'in 1842, and he refers to "Gray 

 MS. in Mus. Brit.," figuring a specimen which I have, I believe, 

 succeeded in tracing (so-labelled), and which belongs to the large 

 depressed form (I). Reeve gives no diagnosis and does not refer to 

 Sowerby's paper in the Proceedings of the Zoological Society, 1843, 

 though it may possibly be that they are nearly of the same date. One 

 reference, to " Sowerby, Sp. Conchyl., f. 9, 10," I have entirely failed 

 in tracing : so far as I know only one portion of the '"Species Conchy- 

 liorum" appeared, and this did not relate in any way to land opercu- 

 lates. Included in my copy of the '"' Malacological and Conchological 

 Magazine " there a})pear, in both parts (1838 and 1839), advertise- 

 ments stating that the author "is actively engaged in completing the 

 second and third parts of the Species Concliyliorum, of which all the 

 plates are engraved, some are printed off and coloured : and all 

 the manuscript is ready, a part of that also being printed off." It 

 may well be that proof copies were distributed and that from one of 

 these Reeve was quoting, and that these plates were used in the early 

 parts of the " Thesaurus." From a copy of one of the covers of the 

 " Thesaurus," preserved in the British Museum, I find that in 1845, 

 only one part of the " Species Concliyliorum " was advertised for sale. 



In 1843 Sowerby gave a latin diagnosis, but no figure, and his 

 description is somewhat vague, but one or two points may be gleaned. 

 Firstly, the habitat is Panama, which agrees with that of the shell I 

 now identify. Secondly, the shell has a ^^coi-tiea, fu/va" periostracum, 

 and he makes no mention of any darker coloured bands ; further, 

 though no size is given, the very name implies that it is about the 

 largest species he knew; also the shell is " (Ji-hirtcIafo-snhilepyt\^sa" 

 and the apex is " nifescente." One point of difficulty in referring 

 this to Form I is that he describes the operculum, and this I am 

 unacquainted with in that form. The colour does not tally with 

 F(jrm II, and Vo\-m III would not be well characterised as '^ orhicu- 

 lahhxah'lepressa.'' I think tlierefore that the diagnosis refers to Form I. 

 When however we come to the "Thesaurus" we find that the figure 

 is darkly banded and resembles I''orm II, while the latin letler[)ress 



