68 Botanical Society of Edinburgh. 



15. RissoiNA NODtciNCTA, A. Adams. R. testa sabnlato-tur- 

 ritd, alba, solidd, anfractibus 10-12, convexis, longitudinaliter 

 plicatd, plicis anyiistis, distantibus, transverslm tenuissime stri- 

 ata, in medio anfractuum cinyuld elevatd ad plicas nodosd, or- 

 natd, suturd nodulis moniliformibus cinctd; aperturd semiovatd, 

 antice subcanaliculatd ; labia antice eallo terminato; labro dila- 

 tato, extiis incrassato, marginejiexuoso. 



Hab. Isle of Capul, Philippines. Mus. Cuming. 



16. RissoiNA c^LATA, A. Adams. R. testd subvlato-tnrritd, 

 albidd, solidd ; anfractibus octo, eonvexiusculis, supremis cla- 

 thratis, ultimo cingulis elevatis, cequalibus, subdistantibus, 

 transversis, interstitiis lineis elevatis, longitudinalibus et trans- 

 versis, deeussatim ornato ; aperturd semiellipticd, antice sub- 

 canaliculatd ; labia calloso ; labro antice dilatato, margine in- 

 crassato, subreflexo. 



Hab. Siquijor. Mus. Cuming. 



The two following species are true Rissoce, characterized hy the 

 simple aperture, which is not channeled in front, and by the absence 

 of the calcareous appendage to the operculum. Many species of 

 small shells have been inaccurately referred to Rissoa, some of which 

 belong, however, to entirely different families. 



Rissoa bella, A. Adams. R. testd turrito-subulatd, albd, 



solidd J anfractibus quinque, planiusculis ; spird apice obtusa, 



" lineis transversis, elevatis, concentricis, canfertis, ornatd ; 



aperturd avali, antich integrd ; labia subcalloso ; labro sub- 



dilatato, extus marginato, margine flexuoso. 



Hab. Philippine islands. Mus. Cuming. 



Rissoa elegans, A. Adams. R. testd subulato-turritd, albd, 

 semipellucidd ; anfractibus 7, convexiusculis ; suturd canalicu- 

 latd, lineis elevatis transversis concentricis et longitudinalibus 

 concinne decussatd ; aperturd ovali, subproductd, antice inte- 

 grd ; labia calloso ; labro antice dilatato, extiis varicoso, mar- 

 gine acuta, subreflexo. 



Hab. Philippines. Mus. Cuming. 



botanical society op EDINBURGH. 



The Society opened their Eighteenth Session on Thursday, No- 

 vember 10th, — 



Professor Balfour, President, in the Chair. 



Dr. Balfour, in taking the Chair, alluded to the value of the Society 

 as a means of keeping up a friendly intercourse among those who 

 were prosecuting the science of botany. He noticed the recent 

 researches in regard to the class of plants called Diatomaceae, and 

 stated that a large microscopical collection had been made at the 

 Botanic Garden, and that the specimens would be exhibited during 

 the Session. 



