29 



DESCRIPTIONS OF CYCLOSTREMA PRESTONI AND NASSA 

 TINBALLI, N.spp., FEOM CEYLON. 



By J. Cosmo Melvill, M.A., F.L.S. 



Head Sth December, 1905. 

 Ctclostrema (Delphinoiuea) Peestoni, D.sp. PI. Ill, Figs. 8, %a. 



C. testa depressa, tenui, cornea, late ximbilicata, albo-pellucentc, 

 Isevi, anfractibus 4, apicali paivo, vitreo, cseteris apud sutiiras 

 impressis, ultimo anfractu conspicue semi-evolvente, apertura rotunda, 

 labro tenuissimo, continiio. Alt. r25, diam. 3 mm. 



iZ"rt5.— Ceylon (H. Nevill). 



A most interesting form. In the evolution of the body- whorl to 

 some extent comparable with C. {Daronia) suhdisjunctum, A. Ad., 

 found in the same seas. The texture, however, is more that of the 

 typical species of the section Delphinoidea, Brown, = Tuhiola, Adams, 

 in parte. I do not think, indeed, it can be subgenerically separated 

 from such species as the British serpuloideum, Mont., excavatum, 

 Watson, from Culebra Island, West Indies (Challenger Exped.), etc. 



I am indebted to Mr. Hugh B. Preston for having supplied me with 

 several examples of this species, and for aiding me in its elucidation, 

 and have pleasure in connecting his name with it. 



Nassa (Hima) Tindalli, n.sp. 



N. testa ovato-fusiformi, solidula, ochraceo-cincrea, zonis rufo- 

 brunneis indistincte spiraliter cincta, anfractibus 8-9, quorum ti'es 

 apicales vitrei, cinereo-brunnei, laevissimi, tertio spiraliter unicarinato, 



caeteris apud suturas gradatulis, longitudinaliter costatis, costis nitidis, 

 gemmulatis, ad ultimum numero 16, omni superficie spiraliter lirato- 

 sulcatis, sulculis arctis, apertura ovata, intus pallide brunnea, vel, 

 rarius violascente, labro albo, nitido, extus et intus denticulato. 



