GASTROPODA. 



[Pulmonata. 



>'inbryonic 1| whorls spirally striated ; aperture crescentric, scarcely 

 oblique ; peristome thin, shortly reflexed at the columella ; parietal 

 wall nude. 



Distribution. New Zealand, Tasmania. Australia. 



Remarks. The genus Monomphalus, Ancey, 1882, from New Cale- 

 donia, is very similar in shell-characters, and the two may require to 

 lie united. However, the anatomy of the New Caledonian forms is 

 unknown, and may prove sufficiently different. (Pilsbry.) 



A. Shell iniperforate. KKY T0 SPECIES. 



a. Spire-whorls with sharp riblets, body-whorl plaited or 

 striated with growth-lines ; spire one-third the height 

 of aperture ; shell 14'5 mm. by 10 mm. 

 All whorls, except protoconch, radially costate. 



an. 



1. 



2. 



4. 



5. 



Costae 4 per millimetre ; spire one-fourth the height 



of aperture ; shell 10 - 5 mm. by 1 mm. 

 Costse 5-6 per millimetre ; spire half the height of 



aperture ; shell (> mm. by 3 mm. 

 Costse 6-7 per millimetre ; spire one-third the height 



of aperture ; shell 7 mm. by 4 mm. 

 Costse 8 per millimetre ; spire half the height of aper- 

 ture ; shell quite white, 5 mm. by 3 mm. 

 Costse 12 per millimetre ; spire one-third the height 



of aperture ; shell 4'5 mm. by 2 mm. 

 Shell narrowly umbilicate or perforate. 



a. Cost* about 20 per millimetre on the whorls succeeding 

 the protoconch, increasing to 40 and 50 on the last two 

 whorls ; shell 4 mm. by 3 mm. 

 'id. Costse nearly equidistant on i>Jl whorls. 



1. Costse 7 per millimetre ; spire one-third the height of 

 aperture ; perforation narrow, sometimes partly 

 covered ; shell 3'25 mm. by 2 mm. 



'2. Costae 8 per millimetre, oblique, retractive ; spire 

 one-fourth the height of aperture ; perforation open, 

 one-tenth of greatest diameter : shell 5 mm. by 

 2-5 mm. 



.'j. Costse 8-9 per millimetre ; spire dome-shaped, half the 

 height of aperture : perforation almost quite closed ; 

 shell 4 - 5 mm. by 3-2 mm. 



4. Costse 9 per millimetre, straight ; spire flat, but little 

 raised ; perforation open, one-tenth of greatest dia- 

 meter; shell 4'5 mm. by 2-5 mm. 



n. Costa? 10 per millimetre ; spire half the height of 

 aperture; perforation narrow, ' mm., open; shell 

 5 mm. by 2-8 mm. 



6. Costse 20-25 per millimetre : perforation narrow, 



sometimes partly covered. 

 a. Spire slightly elevated, two-thirds the height of 



aperture ; shell 4 mm by 1-75 mm. 

 aa. Spire more depressed, one-quarter the height of 



aperture : shell 3'75 mm. l>y '2 mm. 



7. Costse 25 per millimetre ; spire quite Hat : perforation 



narrow, open ; shell 2 25 mm. by 1-25 mm. 

 Costse 40 per millimetre ; spire half the height of 

 aperture; umbilicus one-sixth of 'jrrat^st diameter, 

 open ; shell 1 '5 mm. by 1 mm . . 



Cassandra. 



dimorph us. 

 venulafn-'i. 

 Cooper i. 

 chion. 

 Tullia. 



gramnii. 

 wairoaensis. 



8. 



Godeti. 



Mosgi. 



Adriana. 

 plan ulatus. 

 Smithi. 



Urquharti 



