OF CONCHOLOGY. 3U 



(of the aperture) is always in inverse ratio to the size of the 

 shell, and increase in size as the shell diminishes." Confound- 

 ing, evidently, Mesodon, Xolotrema, Triodopsis and Dsedalo- 

 chila, under the name of Triodopsis, he quotes H. major and 

 albolahris, not toothed; S. thyroides, with a single tooth; H. 

 tridentata, with three teeth, &;g. The smaller shells [Dsedalo- 

 chila) with large teeth. Correcting his errors, we do not find 

 that his position is good, regarding the shells cited and their 

 allies; for in Mesodon, we find albolahris (sometimes), pro- 

 funda^ tSayi, thyroides, all large species, toothed; while the 

 smaller ones are nearly all edentate, as ff. clausa, Mitchelliana^ 

 Pennsylvanica, &c. Again, Triodopsis is characterized through 

 all its species by the tridentate aperture, and some of them 

 are- as large or larger than the last cited species of Mesodon. 

 As for his citation of the species of Deedalochila in this com- 

 parison, we think Mr. Morch might as rationally compare Ari- 

 anta arhustorum with Isognoinostoma (Triodopsis) personata. 



Additions au genre Scissurella: BY O. SEMPER. 



S. Beyrichi. S. Koeneni. 



S. Philippiana. S. Hoernesi. 



Notice preliminaire sur la famille des Diplommatinacees : 

 BY O. SEMPER, 



This includes a catalogue of the species, with their locali- 

 ties. 



Addition au Catalogue des Diplommatinacees: BY O. 

 SEMPER. 



Note sur les genres Julia et Prasina: BY O. SEMPER. 



Description de Cdnes nouveaux provenant de la collection 

 Guming: BY H. CROSSE. 



C. Moussoni^ Seychelles. 0. signifer, ? 



" mirmillo, ? " Macei, India, 



" Carpenteri, N. Guinea. " circumsignatus, ? 



"■ secutor, ? " tribunus, California. 



" anabathrum, ? " archetypus, ? 



" Lizardensis, Lizard I. " anaglypticus, Antilles. 



'' Frauenfeldi, Madagascar. 



Diagnosis Castalise novse: by J. G. hidalgo. 

 Gastalia Grosseana, Equador. 



Diagnosis Turbinellae novse: BY H. CROSSE. 

 Turhinella Sidalgoi, ? 



