NATURAL SCIENCES OF PHILADELPHIA. 483 



Rocellaria indistincta, H. and A. Adams, Genera, ii. p. 336, 1856. 



Description. " R." testa, ovato-elongata, angusta, cuneiformi, tenui, alba, 

 oblique truncata, elongato-hiante, biatu elongato, acuminato, angusciusculo, 

 usque ad tertiarn partem posticam testae attiugente, transversim striata, striis 

 antice tenuibus, regularibus, sublamellosis, erectis, in medio paulo distanti- 

 oribus, et minus regularibus in area postica tenuissimis ; area postica elongato- 

 angusta, angulo obtuso-distincta, ; latere antico brevissimo, ligamento angu3- 

 tissimo, partim infosso, breviusculo." Deshayes. 



Hab. Singapore. Coll. Cuming. 



18. R. interrupta, Desbayes, sp. 



Gastrocbaena interrupta, Deshayes, Zool. Proc. p. 329, 1854. 

 Rocellaria interrupta, H. and A. Adams, Genera, ii. p. 336, 1856. 



Description. "R. testa elongato-angusta, convexiuscula, extremitatibus 

 fere sequaliter lata, per longitudinem quasi excisa, late aperta ; biatu longis- 

 simo, ovato, oblongo, inferne vix acuto, et fere totam longitudinem testae 

 aequante ; valvis oculo nudo lsevigatis, sublente argutissime striatis, striis 

 obsoletis, distantibus, incrementi distantibus, subcontabulatis, interruptis ; 

 margine inferiore recto, superiore fere parallelo, umbonibus minimis, sub- 

 terminalibus ; latere antico brevi, inclinato ; ligamento angustissimo, brevi." 

 Deshayes. 



Hab. Philippines. Coll. Cuming. 



19. R. lamellosa, Deshayes, sp. 



Gastrochaena lamellosa, Desbayes, Zool. Proc. p. 328, 1854. 



Rocellaria lamellosa, H. and A. Adams, Genera, ii. p. 336, 1856. 

 Description. " R. testa elongato-angusta, tenui, fragili, Candida, hyalina, 

 compressiuscula, longe hiante, margine antice paululam excavato, in medio 

 convexo, biatu longissimo, inferne valde attenuata, fere totam altitudinem 

 testa? aequante ; valvis antice valde attenuatis, rostratis, postice obtusis, 

 rotundatis, antice tenuissime striatis, striis erectis, appressis, in medio dis- 

 tantioribus, breviter lamellosis, eleganter armatis, regularibus ; umbonibus 

 minimis, approximatis, subumbilicatis ; latere antico brevissimo, subrostrato ; 

 ligamento angustissimo, nigro." Deshayes. 

 Hab. Philippines, Zebu. Coll. Cuming. 



20. R. Philippinensis, Deshayes, sp. 



Gastrochaena Philippinensis, Deshayes, Zool. Proc. Lond. p. 328, 1S54. 

 Rocellaria Philippinensis, H. and A. Adams, Genera, ii. p. 336, 1856. 

 Description. "R. testa elongato-angusta, subovata, compressiuscula, tenui, 

 alba, antice inferneque oblique hiante, hiatu ovato, inferne acuminato, di- 

 midiam partem testae paulo superante ; valvis tenue striato-lamellosis ; striis 

 arcuatis, secundum peripheriam valvarum antice tenuibus, approximatis, in 

 medio latioribus, sublamellosis ; margine superiore postico paulo carinato ; 

 umbonibus minimis ; latere antico brevi, recto, subrostrato." Deshayes. 

 Hab. Philippines, Zebu. Coll. Cuming. 



21. R. R u p p e 1 1 i i , Deshayes, sp. 



Gastrochaena Ruppellii, Deshayes, Zool. Proc. Lond. p. 328, 1854. 

 Rocellaria Ruppellii, H. and A. Adams, Genera, ii. p. 336, 1856. 

 Description. "R. testa elongato-ovata, solidula,, turgidula, candid i, antice 

 oblique hiante ; hiatu ovato, late, infere attenuate, fere totam altitudinem 

 testae aequante ; valvis dense striatis, striis obtusis, antice satis regularibus, 

 appressis, in medio et latere postico distantioribus, irregularibus, obtusis ; 

 umbonibus tumidulis ; latere antico brevi, recto, antice parum inflexo ; liga- 

 mento praelongo, angusto." Deshayes. 



Hab. Red Sea. (Ruppell.) Coll. Cuming. 



1861.] 



