HEMISINUS. 



Plate I. 



Genus HEMISINUS, Sicainson. 



Testa nunc glolosa nunc elongata, plerumque solidiuscula, 

 olivacea, srepe spiraliter rufo-punctata, anfractibus vel 

 lavibus vel liralis. Apertura ad basin emarginata, 

 columella plus minus calloso-contorta et iruncata. 



Shell sometimes globose, sometimes elongated, generally 

 rather solid, olive, often spirally red-dotted, whorls 

 smooth or ridged. Aperture notched at the base, 

 columella more or less callously twisted and trun- 

 cated. 



It is chiefly to the assiduity of Professor Behn, of Kiel, 

 during the voyage of the Danish man-of-war ' Galatea,' 

 that we are indebted for the discovery of an assemblage of 

 Melaniada>, presenting a speciality of character which had 

 been indicated by Mr. Swainson some years ago in a 

 single odd species. In searching about the district of Per- 

 nambuco, among the tributaries of the Amazon, he found 

 the Melaniadee to be all more or less distinguished by a 

 notched base and callously twisted columella ; and we have 

 availed ourselves of the specimens communicated by him 

 to Mr. Cuming, to raise the genus Hemisinm to a rank of 

 more importance in the family. 



Of the twenty-six species comprised in this genus, a few 

 have been described, by Lea, Morieand, Gray, and Poey, 

 as Melauitp, but more than half of them are new. 



All the Hemisini are from Brazil or Venezuela, except- 

 ing a few species partaking little of the typical characte- 

 ristics of the genus. Two small species inhabiting the 

 Seychelle Islands come into the group and three from 

 Illyria, Java, and Borneo. 



Species 1. (Fig. a, b, Mus. Cuming.) 



Hemisinus punctatus. Hem. testa ovalo-tnrbiuatd, 

 subventricosd, luteo-olivaced, rufo sparsim transverse 

 punctata, anfractibus septem ad octo, leevibus, spirali- 

 ter lineari-sulcatis, sulcis mediants plus minus obso- 

 letis ; apertura ovatd, columella calloso-excavald et 

 contortd. 



The dotted Hemisinus. Shell ovately turbinated, some- 

 what vcntricose, yellowish-olive, sparsely transversely 

 dotted with red, whorls seven to eight, smooth, spi- 

 rally linearly grooved, middle grooves more or less 

 obsolete ; aperture ovate, columella callously exca- 

 vated and twisted. 



Hab. Pernambuco. 



A rather ventricose shell, covered with a shining, obso- 

 letely-grooved, yellowish-olive epidermis, and sprinkled 

 promiscuously at rather distant intervals with transversely- 

 dashed red dots. 



Species 2. (Fig. a, b, Mus. Cuming.) 



Hemisinus bicinctus. Hem. testa turriculatd, solidi- 

 uscula, olivacea, fasciis duabus castaneis angustis dis- 

 tantibus cingulatd, anfractibus octo, superni concavo- 

 declivibus, delude convexo-planis, /iris spiraliter un- 

 dif/ue fuuiculalis, interstitiis excavatis ; apertura par- 

 vinsculd, labro superne sinuato, columella rigide cur- 

 ni/ii. 



The two-banded Hemisinus. Shell turriculated, rather 

 solid, olive, encircled with two narrow, distant chest- 

 nut bands, whorls eight, concavely sloping round the 

 upper part, then couvexly flattened, spirally corded 

 throughout with ridges, the interstices between which 

 are excavated ; aperture rather small, lip sinuated at 

 the upper part, columella rigidly curved. 



Hab. Brazil. 



It is somewhat doubtful whether this is distinct from 

 H. Brasiliensis, represented at Fig. 5 a, b. It is of rather 

 solid growth, very regularly corded throughout, and en- 

 circled with two characteristic chestnut bands, little seen 

 externally through the epidermis, but plainly shown in 

 the interior. 



Species 3. (Fig. a, b, Mus. Cuming.) 



Hemisinus Buccinoides. Hem. testa fusiformi-turbi- 

 ■na/d, versus basin ventricosd, luteo-fuscd, rufo spirali- 

 ter interrupts lineatd, anfractibus septem ad octo, Ia- 

 mbus, superne declivi-impressis, ultimo medio gibboso ; 

 apertura oratd, columella superne callosd, inferne cal- 

 loso-contorta. 



The Buccinum-like Hemisinus. Shell fusiformly tur- 

 binated, ventricose towards the base, yellowish-brown, 

 whorls seven to eight, smooth, slopingly impressed 

 round the upper part, last whorl gibbous round the 

 middle; aperture ovate, columella callous at the 

 upper part, callously twisted below. 



Hab. Jamaica ? 



January, 1860. 



