BLANFORD: ON RAIOSTOMA DALYI AND SESARA MEGALODON. 39 
of this section of Rhiostoma, R. Housed (Haines) from Cambodia and 
Rh. (Pterocyclus) Muriont, Ancey (Bull. Mus. Marseille, 1898, 1, p. 187, 
fig.), have the free part of the last whorl much more elongate. 
&. Dalyi was obtained by its discoverer only in one locality, near 
Pitsunaloke, in very damp and dense forest. It was not common. 
2. SESARA MEGALODON, 0.sp. 
Testa imperforata, depresso-conoidea, fusco-fulva, cornea, superne 
transversim costulis minutis confertis, infra peripheriam evanescentibus 
ornata, subtus levis, polita, radiatim striatula; spira conoidea, apice 
obtuso, sutura impressa; anfr. 7 convexiusculi, lente accrescentes, 
ultimus ad peripheriam rotundatus, subtus convexus, medio ad 
periomphalum excavatus; apertura obliqua, angusta, dentibus quatuor 
ineequalibus, uno minore, aliquando fere obsoleto, in margine dextro, 
uno parvo columellari, duobus basalibus, interno mediocri, externo 
magno, lato, coarctata; peristoma albidum obtusum, intus incrassatum, 
margine basali inter dentes profunde concavo, columellari vix expansulo. 
Diam. maj. 10, min. 9°25 mm.; alt. 6 mm. 
nN 
Fie. 11.—Sesara megalodon, n.sp. 
Hab.—Pitsunaloke, Siam. 
This Sesara is near S. infrendens (Gould), and I at first took it for 
a variety of that species, from which, however, it is distinguished 
by its very different aperture, with four teeth instead of three, 
by the different arrangement of the teeth, by its much excavated 
periomphalus, and by its larger size. The large outer tooth in the 
basal margin represents the two outer teeth of S. infrendens, an 
approach to the present species being made by the partial union of 
these teeth in S. infrendens var. Tickelli. 
This species-is stated by Mr. Daly to be common at Pitsunaloke in 
evergreen forest. 
