SVKES : MALACOLOGICAL NOTES. tCj 



relates to Form I, and the English apparently to both. Probably he 

 considered both to be varieties of one species. The references by 

 Gray in 1850 and 1852 relate, no doubt, to Form I. 



In 1846 Form III first appears on the scene, being figured by 

 Pfeiffer, and he notes that the form figured in the "I'hesaurus" (Form 

 II) is larger and more depressed. The shell figured by Reeve in 1863 

 as a Cijrlutus is, I feel sure, Form II ; he gives a fresh diagnosis and 

 suggests that " this fine species should be regarded as the type of the 

 genus." 



In 1867 Hidalgo described C'l/cloftis fisclipri, which later on he 

 sank as a synonym of (jiijantene. 



Later authors throw but little light on the difiiculty, and I there- 

 fore suggest the following as the best course. 



That the name gigautcnin be used for the large depressed form, 

 which has no dark colour bands. I have seen several specimens, 

 which are constant, and it comes from Panama (coll. Boucard), the 

 original locality given. That the w^me. livelier i be used for the smaller, 

 not so depressed form, with corrugated sculpture on the upper surface 

 and darker bands of colouring; this comes from Ecuador (Hidalgo, 

 etc.); Isle of Tumaco (Jay). Very possibly the shells referred to 

 C. gvjanteus by Bland (Contrib. Conch., p. 228), and collected in 

 "New Granada," belong here, as he refers to Sowerby's figure ill the 

 " Thesaurus." 



I propose the name confusum for the well elevated shell, with a 

 strong sinuation at the top of the outer lip, and the same general 

 colouring as gigantenm. This is the shell which Prof, von Martens 

 refers to when he states (Biol. Centrali-Amer., MoUusca, p. 598) "This 

 species \jjiganteum\ is mentioned by Boucard among the shells from 

 Vera Paz (N. Guatemala) , probably an error in determina- 

 tion, as 0. giganteus has not been recorded by anyone else from so 

 far north as Guatemala." I have specimens from Mons. Boucard. 



A few remarks in conclusion as to the generic name to be used 

 for these shells. 



Aperostoma was proposed by Troschel (Zeitschr. f Malak., 1847, 

 p. 44) for " volvulus, Lam., m."xlcanum, Mke., hianchefiamim, jNIoric, 

 und viele andere." Later on in the same volume (pp. 47, 104) Pfeiffer 

 removed volvulus to Cij clop] ion is and left, with a number of other 

 species, Ijoth mex/ranum and hlanchi'tianum in A/>ew-ioma, adopting 

 the generic name. In 1852 Morch (Cat. Voldi, \>\). 39, 40) placing 

 Aperostoma as a synonym of djclotus — which was proposed for very 

 different shells — left hlanclietianum ( = inca) there, and proposed djiio- 

 toma for iiic.ricaiiuin. In 1S55 the brothers Adams in their " Genera" 



