60 MR. HARPER PEASE ON THE AURICULIDEH. — [Jan. 28, 
entire, short, extending but a short distance beyond the aperture, 
bluntly rounded behind. Tentacles short, stout, cylindrical, obtuse 
at their ends; eyes immersed at their posterior inner bases. 
Genus BLaunerta (Shuttl.). 
The animal of B. gracilis, Pease, inhabiting the Sandwich Islands, 
differs so widely from that of B. pellucida, as described by Gund- 
lach and Binney*, that I am disposed to regard it as a distinct 
genus, although the shells can scarcely be distinguished. Mr. 
Binney appears to have been acquainted with but one species. Four 
have been described, three of which are in my collection. That in- 
habiting the Sandwich Islands is the largest, attaming to 8 mill. in 
length. 
The animal of B. gracilis is small in proportion to the size of 
the shell, the head projecting but slightly from the shell, and the 
foot extending just beyond the aperture. It is pellucid, colourless, 
excepting a yellowish tinge around the mouth. Tentacles short, 
stout, approximating at their bases. Head narrow above, and much 
dilated below; mouth a simple longitudinal slit. Foot small, short, 
bluntly rounded behind, truncate in front, divided by a transverse 
groove, the posterior segment being slightly the longer. Eyes con- 
spicuous, black, immersed at the posterior bases of the tentacles. 
B. pellucida is reported to have been found at Washington city 
in gardens. The above species is marine, or at least amphibious. 
Its station is similar to that of Pedipes, which is found in the cre- 
vices of stones overflown at high water. I have never found B. 
gracilis on the sides or tops of stones when the tide was out, but 
around their bases where the water stood in little pools. 
Genus Trai (Gray). 
The animals of the two species of this genus inhabiting the Sand- 
wich Islands are those of true Melampi; their shells are strictly 
Tralie, being furnished with three internal elevated ridges on the 
outer lip, not dentate or plicate near the edge. 
Mexampus (Traut) semrpiicata, Pease, P. Z. 8.1860, p. 146. 
Animal: proboscis rather narrow, emarginate in front, finely 
wrinkled transversely, blackish on its upperside. Tentacles when 
extended elongate, cylindrical, somewhat enlarged near the base, 
obtuse, terminating in a slight round knob, transversely grooved, 
black at the tips, shading off into cimereous at their bases. Foot 
divided by a transverse groove at about one-third of its length ; 
anterior segment bluntly rounded in front, concave behind ; poste- 
rior segment bifid at its termination by a short slit. It moves by 
advancing the anterior portion of the foot, and then drawing up 
over it the hinder part. Its motion is regular, similar to that of the 
Helices—giiding along, when on a smooth surface, rather quickly. 
* Land and Freshwater Shells of North America (Smiths. Institution), 1865, 
part 2, p. 20. 
