THALA. 



M. SEMISTRIATA, Krynicki. Uaspian Sea. 



M. ORDINATA, Pease (ubi) Pastel's Catalogue. 



Sandwich Islands. 



M. SECTILIS, M. PALLIDA, Pease. Sandwich Islands. 



M. OBSCURA, Humphrey ; M. MUTELINA, Duclos ; M. GLOBOSA, 



Ghemii. ; 'M. CINCTA, Meuschen. H. & A. Adams' Genera of 



Shells. 

 M. TASMANICA, LEGRANDI, SCALARIFORMIS, SEMILIVIDA, FRANCIS- 



CANA, GRANATINA, Tenisoii-Woods. Tasmania. 



M. RUSSA, Gould. China Seas. 



M. SECALINA, Gould. Ousima. 



M. L^TA (China Seas); M. DELICATA (Cape York, Australia); 



M. ASPERULATA, (Australia); M. RETICULATA (Port Essing- 



ton, Australia) ; M. PALLID A (Marquesas) ; M. ( YOLUTOMITRA) 



CINNAMOMEA (Natal); M. PUNCTOSTRIATA (Ceylon). All of 



Arthur Adams. 

 M. ANTONI (Sandwich Islands) ; M. GIBBA (New Caledonia) ; M, 



AUTUMNALIS (New Caledonia), of Dohrn. 



M. LEUCOSTOMA, Swainson. No locality. 



M. INTERSCULPTA, Sowerby. . Mauritius. 



M. HUMERALIS, Garrett. Paumotus Is. 



Genus THALA, H. and A. Adams. 



Mr. Garrett remarks * that some of the species included in 

 this genus are Pleurotomoid shells ; that the wrinkles or folds on 

 the columella are not true plaits, but simply more or less irreg- 

 ular transverse rugosities, precisely of the same structure as 

 observed in certain species of Clathurella and Cithara. Some of 

 the species which he declares should be excluded from Mitridae, 

 appear to me to possess the character of the family, whilst in 

 others, so minute are the specimens that it is difficult to decide 

 whether they have plaits or not the difficulty being enhanced 

 by the poor state of preservation of several individuals. M. 

 todilla, Mighels is one of the excluded species, yet it possesses 

 them, as mentioned by Dr. von Martens. Of course the difficulty 

 of deciding is enhanced with those species of which figures only 

 are accessible. Unfortunately the animal is unknown ; this is 



* Leeds Jour, of Conch., iii, 2. 



