﻿P L A N R lU S. 



Species 77. {Vig. a, l, i[ns. Hanley.) 



I'l.AN-ORBIS UMBII.lGAt.IS. Fl'i. I'.^ln Jrjf rail', .-■r./hiculali'!, 

 fusca,ttinul, nitenti, !" i-'nj:il>!. <i'ini-if' fiinnJn, iHjrn 

 planii'ifculo, infra iiifiliiun curimilil ,• spii-:! iimjiiitd, 

 planatd; anfradihus trihus, uUlnw macjtw. Into, 

 xiipra carinam tuinido ; aperturd ollicjue lata, 

 margtiie suijeriori siimatim producfo, disco inferiori 

 medio anguste iimbilicato. 



The umbilical Planorbis. Shell dextral, divided in 

 segments, brown, thin, sliining, smooth, tumid 

 above, rather flat below, keeled below the middle; 

 spire narrow, flat ; whorls three, last large, 

 broad, tumid above the middle ; aperture ob- 

 liquely broad, upper margin sinuously produced, 

 lower disc naiTOwly umbilicated in the middle. 



Benson. Journ. Asi. Soc. Bengal, Vol. V. p. 741. 



Hiilj. East Bengal. 



Species 78. (Fig. a, b, Mus. Hanley.) 



Plan'OEBIS ciENOsus. Pla. fcsld dextrali, segmentald, 

 pii-iUidii suhcirldi, J(vvigatd, superne truncato-conied, 

 infra inilipJanuhil<i. imilio anguste mnhilicata ; 

 spird aiignstif:sirih!, tiltitiin wiifractu latissivw, infra 

 ■hieih'inii itriij: run'iiiilo ; aperturd trigond, margitie 

 siipn'i ihfr.'i.jw jh'j nn^ini depresso. 



The miky Plani.ii;i;is. Shell dextral, divided in seg- 

 ments, gi-eenish, smooth, truncated-conical above, 

 rather flat below, narrowly umbilicated in the 

 middle ; spire very narrow, sharply keeled below 

 the middle ; apertui-e trigonal, margin flexuously 

 depressed above and below. 



Bexson. Ann. Nat. Hist. 18.::iO. p. 341t. 



Uah. Near Moradabad, Ceylon. 



Species 79. (Fig. a, h. Mus. Hanley.) 



Planoebis Cantoei. Pla. tedd sordide sicbviridi, 



dextrali, segmentatd, siipcme twniida, infra con- 



vcxiiiscjdd, medio tunbilitatd; spird latiuscidd, 



ultitm aiifraciu lata, infra medium obtuse carinato; 



apirliird sidjlrigond, murgine snpentr jlr.iitvsiiu 

 produclo. 



Cantor's Planorbis. Shell dull greenish, dextral. 

 divided in segments, tumid above, convex below, 

 umbilicated in the middle ; spire rather broad, 

 last whorl broad, obtusely keeled below the 

 middle ; aperture i-ather trigonal, upper mftrgin 

 flexuously produced. 



Benson. Ann. Nat. Hist. 1850, p. ?,V.K 



Hah. Barrackpore, India. 



Species 80. (Fig. a, h, Mus. Biit.) 

 Planorbis Ponsonbyi. Pla. testd diMfntIi, ulli^yi.in!, 

 ventricosd, albd, epidermide tenui pallidr jlatidd 

 indutd, supernii subconicd, infra lat'e et profimde 

 umbilicatd; spird sulfurritd ; nnfractibus dmobus, 

 hrrril,,.., s>i',„„,,,d.,i;^<. idliiun oiifrarl ii ^..^.rnie 



i'hu>'d.,h. ■,;„;h.,.,.,,.ri..r;;.f.r;..r:.,.r.:,ri. 



supernii e.tpansd. 

 Ponsonby's Planorbis. Shell dextral, very high, 

 ventricose, white, covered with a yellowish thin 

 epidermis, a little conical above, broadly and 

 deeply umbilicated below ; spire subturreted ; 

 whorls two, short, i-ather angular, last whorl 

 flattened above, upper and lower margin keeled : 

 aperture broad, rather trigonal, acuminated be- 

 low, expanded above. 

 Smith. (Cariuifex.) Proc. Zool. Soc. 187-5, No. li. 

 Huh. California. 



In Planorbis hicarinata and PI. aurifa, the spire is 

 sank, and not, as in this species, esserted. Other- 

 wise, the two former much resemble the latter. I 

 cannot see any reason for separating these shells 

 generically. At least one very different species has 

 an exscrted spii'e. 



Species 81. (Mus. Brit.) 

 Planorbis Newbereyi. Pla. testd Jejlmli. idiiss 

 ventricosd, corned, epidertaide tenui iiuli'td. i 



