Buitendijk. 



This form, which is doubtless a young stage, cannot, 

 however, be referred with certainty to any known species. 

 The embryonic shell, as well as the dorsal ribs, is most 

 like that of Diacria. Perhaps it may be identiöed with 

 Diacria quadridentata. 



» Cleodora compressa' Souleyet. 



Animals : 

 Indian Ocean, August '06, some sp.. Buitendijk. 



Almost certainly to be referred to Diacria trispinosa. 



^Hyalaea laevigata'^ d'Orbigny. 



Animals : 



Indian Ocean, January '06, 2 sp.. Buitendijk. 

 // April '06, I sp., // 



Young stage of Cavolinia longirostris. 



» Pleuropus longijilis'^ Troschel. 



Animals : 

 Indian Ocean, March '07, 1 sp.. Buitendijk. 



Empty shell: 

 Mediterranean (Sicily), date?, 1 sp., Cantraine. 



Young stage of Cavolinia tridentata (see especially 

 Schiemenz, PI. 1, figs. 1 — 7). 



Notes from the Leyden Museum, Vol. XXIX. 



