50 



PHASIANELLA. AMPULLARIA. MELANIA. 



Fig. 51. 



PHASIANELLA P1CTA. 



41. The PHASIANELLA (jig. 51) have an 

 oblong or pointed shell ; the aperture is higher 

 than it is wide, and furnished with a strong 

 operculum ; the base of the columella is flatten- 

 ed, but there is no umbilicus. These animals 

 inhabit the Indian Ocean, and their shells are 

 much sought after by collectors, on account of 

 the beauty of 

 their colours. 



42. The 

 shell of the 

 AMPULLARIA 

 (Jig. 52) is 

 round, ventri- 

 cose, with a 



short spire, as in most of the 



Helices ; the aperture is higher 



than it is wide, and provided with 



an operculum ; the columella is 



umbilicated. The Ampullarise 



inhabit the fresh or brackish 



waters of hot countries. Many 



species are found in the United 



States. 



43. The shell of the MELANIA (fig. 53) 

 has the aperture higher than wide, and it 

 enlarges opposite to the spire ; the colu- 

 mella has neither plicae (folds) nor umbili- 

 cus ; the length of the spire is very various. 

 The animal has long tentacles, the eyes be- 

 ing at about one-third of their length, on 

 the external side. The Melaniae inhabit 

 fresh-water rivers ; a number of species is 

 met with in the United States. 



44. The JANTHiTfjE (fig* 54) resemble 

 snails in the general form of their shell, but 



Fig. 52. AMPULLARIA. 



Fig. 53. MELANIA. 



differ considerably from the different mollusks we have described 



41. How is the genus Phasiane'lla characterized ? (Phasianella, from 

 the Greek, Phasianos, a pheasant, because this shell bears some resem- 

 blance to the pheasant in its colours.) 



42. How is the genus Ampulla'ria recognised ? 



43. What are the characters of the genus Mela'nia ? (Melania, from the 

 Greek, melas, black.) 



44. What are the characters of the genus Janthi'na ? (Janthina, from the 

 <5re<?k ianthon, violet colour.) 



