50 



PHASIANELLA.— AMPULLABIA.— MELANIA. 



41. The Phasiattella {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 



Fig. 51. 



PHASIANELLA PICTA, 



their colours, 



42. The 

 shell of the 

 Ampullaria 

 {fig. 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 Ampullariae 

 inhabit the fresh or brackish 

 waters of hot countries. Many 

 species are found in the United 

 States. 



Fig. 52. — AMPULLARIA. 



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 plicse (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 wilh in the United States. 



44. The Janthin^ (j%- ^^) resemble 

 snails in the general form of their shell, but 



differ considerably from the different mollusks we have described 



FiS- 53. MELANIA. 



41. How is the g^enus Phasiane'Ila characterized ? (Phasianella, from 

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

 bl ince to the pheasant in its colours.) 



42. How is the g'enus Ampulla'ria recognised ? 



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

 Gree>k, mplas, black.) 



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

 Gre'jk ianthon^ violet colour.) 



