H Y D A T I N A 



Plate I. 



Genus HYDATINA. 

 IVstii DVfdi-globom, valde ven/ricosa, spird di-jin'ssiiiscHld ,• 

 aperturd ampid, jiostict' i-oan-latd : hthiiim c.iifniiim 

 teuue, actttum ; Ijdninn mlrniUHi hii HisHitiiiiiii , ri'pl'i- 

 eatu.adnaitm : anfraclm h/Iimiis uijhitiit:. 

 Shell ovate-globose, very veutricose, spire rather de- 

 pressed ; aperture wide, contracted posteriorly ; outer 

 lip thin, acute; inner lip very thin, united and rc- 

 Hected ; last whorl inflated. 

 The Mauritius, Ceylon, China, and St. Vincent's, in 

 the West Indies, are the stated habitats of the four spe- 

 cies of Ilydatina at present known. They are nearly con- 

 volute shells, the earliest whorls being sunk even uliere 

 the penultimate is accidentally or specifically exserted. 

 Ill this respect they differ from shells of the genus Jpliis- 

 Iniiii, although the animals of the two genera resemble 

 rach other very closelv. 



Species 1. (Fig. 1, 2, Mus. Cuming in Brit.) 



IIvUATlNA NITIDCLA. //y/. /fstd ovatd, pallidi fulvd 

 eel ffrism, lineis trihus trmnsversis riibris vel rubro- 

 fiiscis, liiwkqui' hwijlludhiitUhiis iimlidutis convolorl- 

 bus jjicid, iraiim-rrv i/r/n/d. ^/riis unhdUiantihiis punc- 

 tata, spird prominiild : apicc ob//iso, aperlurd aiiqild, 

 post ice rniffiistaid, autice vcdidi diluUdi; coluiuelld 

 arcuald, antice rotundatd. 



The neat little Hydatina. Shell ovate, pale fawn 



or grey, painted with three red or reddish-brown 

 transverse lines, and longitudinal undulating lines of 

 the same colour, transversely striated, strife subdis- 

 tant, punctured, ' spire a little prominent with ob- 

 tuse apex ; aperture large, narrowed posteriorly, much 

 I widened anteriorly; coliinulia arched, rounded an- 



teriorly. 

 ! Lister, Hist. Conch, t. 715. f 74. 

 Bidia FeniKnacii, Quoy. 

 Hnb. The Mauritius. 



The tliree neatly-arranged red spiral lines, crossed by 

 undulating concentric ones, distinguish this shell as 

 among the most beautiful of the genus. 



Species 2. (Fig. a, b, c, d, e, Mus. Cuming in Brit.) 



Hydatina 1'hysis. Hyd. tenia omdo-rotundatd, lenni, 

 seniipellucidd, lavigatd, (dbidd, lineis iiiaquaHbiia 

 traiixci'i-sis iiiijresceidibiis pictd, spird coiicavd ; aper- 

 lurd iiKiijnd. aidice diUiUdd : variat lineis rubescenti- 

 biifi niididutis coHceidricis. 



The Pnysis Hy'datina. Shell ovate-rounded, tliin, 

 semipellucid, smooth, whitish, painted with unequal 

 transverse blackish lines, spire concave ; apertui'e 

 large, dilated in front; it varies with undulating, 

 concentric, reddish lines. 



LiNNJius, Systema Nature. 

 Hydatina Jilosa, Schum. 



Hab. The Mauritius; found on clear sand, 



