196 G. LINDSTRÖM, ON THE SILURTAN GASTROPODA AND PTEROPODA OF GOTLAND. 



Additional gemis, the systematic place of which is at present uncertain. 



Gen. ONYCHOCHILUS n. O 



Shell ovate, sinistral, aperture narrow as a slit, oblique, oiiter lip loith thick börder, 

 the inner lip involute, eloiigate and ciirved like a daio, probahly ivith a rudimentary si- 

 phonal notch. The umbilical region is excavated and deepened into a funnel, loide ahove 

 and narrow downioards. 



This genus must remain provisional untill raore specimens have been collected, 

 apt to further elucidate its structure and systematic place. 



1. Onycliocliilus physa n. 



Pl. XV fig. 00—58. 



Shell tumid, ovate, sinistral, whorls four, the last being of more than double the 

 size of all the others taken together. The surface is transversally striated, parallel 

 with the outer lip, the strite fine, like ribs, running nearly straight from the suture to 

 the umbilicus. The aperture is obliquely elliptical, the outer lip thick, turned out in 

 a narrow elevated rim, the inner one involute and the whole side narrow. The um- 

 bilical region is partly destroyed and partly covered as not to be discernible. H. 4 

 millim., br. .3 millim. Another specimen is 8 millim. in height. 



Two specimens, found in the uppermost limestone of Slite by Prof. P. T. Cleve, 

 are preserved in the. Museum of the University of Upsala. 



2. Onycliocliilus reticulatum n. 



Pl. XXI fig. 61—65. 



Shell small, trochoid, obese, whorls four, tumid, body whorl more than twice 

 surpassing the other Avhorls. Their sides are straight or even, only slightly convex 

 and the suture is shallow. The ornamentation consists of fine, longitudinal strige cros- 

 sed by thicker, transverse, elevated ridges, nearly double as large and running obli- 

 quely from the suture backwards to the umbilicus. There are small, indistinct tuber- 

 cles at their meeting. The aperture is oblique and narrow, a little more widened at 

 its superior edge. Both lips are thin and the inner one shows the peculiar, clawlike 

 curvature. The umbilicus is a funnel, wide upwards and narrowing downwards. Sectio- 

 ned longitudinally the whorls show an elongated kidney like shape, being somewhat 

 impressed on the inner side, turned against the umbilical funnel. H. 4 millim., br. .3 

 millim. Three specimens have been obtained from the red limestone of the hill of 

 Sandarfve. 



^) 'Ovvi, claw, )fE'i).ng lip. 



