169 



diagonal furrows, a name has been given to it iu remeinbrauce of the 

 author of the Mouograph in the Proceedings aud Transactions of the 

 Zoological Society. The shell tigured as Calyptrcea imbricata iu the 

 Transactions exactly accords with the young statė of the ordinary 

 thick, ribbed, and often pitted species of the W. American coast, 

 figured by Sowerby under the šame name in his ' Genera,' f. 5. An 

 attempt to remodel the synonymy of this shell will be found in the 

 British Museum Mazatlan Catalogue. 



8. Cyclostrema excavata, n. s. C. t. margaritąformi, nitidiore, 



alba; unfr. nucleosis i\.,lcevibus ; dein anfr. uno et dimidio striulis 

 minimis radiantibus, excurvatis ; dein anfr. ii. et ditnidio norma- 

 libus ; totą svperjicie minutissime spiraliter striatis ; basi regione 

 umbilicali malime excavata ; umbilico profunde spirali, anfractus 

 ultimi dimidio solum monstrante ; apertura subrotundata. 

 Long. -16, long. spir. -08, lat. -24 poli., div. 130°. 

 Hab. In Mari Sinensi. Sp. unic. in Mus. Cuming. 

 This shell appears glossy to the naked eye, and escapes from the 

 fingers likę a Zonites, but under the glass is beautifully sculptured. 

 The first normai whorl appears as though engine-turned. 



9. Cyclostrema octolirata, n. s. C. t. parva, alba, anfr. v., 



ąuorum duo et dimidium nucleosi sunt ; liris acto validis spiralibus 

 cincta, guarum duo in spiram et una vix intus umbilicum maxime 

 apertum sitee sunt ,• sutura profunda ; apertura circulari, anfr. 

 penult. vix attingente. 

 Long. -4, lat. -6, div. 155°. 

 Hab. In Mari Rubro. Sp. un. in Mus. Archer. 

 The umbilicus is so wide as clearly to show the junction of the 

 apical whorls at the top. The species appears too strong, and the 

 adult portion too large in proportion to unite with Vitrinella, with 

 which it agrees in many characters. 



10. ? Cyclostrema pentegoniostoma, n. s. 1 C. t. subdiscoidea, 

 parva, solidiore, alba ; anfr. v., quormn ultimi duo normales sunt ; 

 carinis quinque cincta, una in spira, una valde prominente ad 

 peripheriam, tuberculis obscuris undata, una in basi, duabus infra 

 umbilicum maximum ; totą superficie minutissime et creberrime 

 transversim striata ; apertura circulari, parum attingente, a 

 carinis angulata. 



Long. -04, lat. -065— -09, div. 165°. 



Hab. In Mari Rubro. In Mus. Brit. repertura. 



Known at once from the tricarinate Vitrinellce by its strong growth, 

 the undulating periphery of the principai keel, and the very minute 

 radiating strise. 



11. TViTRENELLA SPIRULOIDES, U.S. V. t. hyalina, diaphan'a, 

 minima, tenuissima ; spira planata, anfr. vix attingentibus, haud 

 rapide augentibus ; liris acutis subdistantibus radiantibus, circiter 

 XX. cincta ; interstitiis tenuissime spiraliter striatis ; peritremate 

 continuo, circulari. 



