OF SOUTHERN INDIA. 47 



POllOMYA, Forbes, 1844, (see p. 38). 

 1. POROMTA GLOBULOSA, Forhes, PI. Ill, Pig. 8 ; PI. XVI, Fig. 16. 



1846. P. glohtdosa, Forbes, Trans., Geol. Soc, Lond., VII, p. 141, pi. 17, fig. 6. 

 1850. Lyonsia id., d'Orb., Prod. II, p. 234 — idem auctorum. 



P. testa inflata, incequilaterali, tenui, antice rotundate imncata, posiice paulnlum 

 attenuata et prodacta, ad terminationem rotandata, coiicentrice miiiutissime striata 

 ao radiatim punctata, punctis in seriehus radianttbus dispositis ; umboiiibiis tmnidis 

 incurvis. 



Height of shell : its length ... ... ... ... 0'89 



Thiokne.s3 „ : ,, ... ... ... ... 076 



Shell strongly globular and short, with the beaks prominent and incurved ; the 

 anterior side is rather truncated, the posterior which is the longer one attenuated, 

 compressed, and rounded. The hinge-teeth have not been observed; the punc- 

 tuations are to be seen, as stated by Forbes, only on the well preserved surface, 

 but when this is a little worn off they disappear altogether. These punctures are 

 connected with very fine radiating lines. The beaks are slightly incurved towards 

 the anterior end. Forbes' figure ought to be more inequilateral, anteriorly much 

 shorter than posteriorly. In our fig. 8 on pi. 3, the striaj on the anterior side 

 ought to be turned more upwards, as shown in the co-rrected fig. 16 on pi. xvi. 



Locality. — In a light coloured sandstone near Comarapolliam ; rare. 



Formation. — Arrialoor group. 



2. PouoMYA LATA, Forbcs, PI. II, Figs. 8-9, and PI. XVI, Fig. 17. 



1846. Poromya lata, Forbes, Trans., Geol. Soc, Lond., VII, p. 141, pi. 15, fig. 14. 

 1850. Lyonsia id., d'Orb., Prod. II, p. 234 — idem auctorum. 



T. testa oblonga, tenui, convcxitiscula, incequilatera, antice breviori; timbonibus 

 prominulis, antice incurvatis ; ad extremitates rotundata, in superjicie polita., concen- 

 trice striata ac punctis distantibus, profundis, in lineis radiantibus paululum elevatis 

 dispositis notata. 



Height of shell : its length ... ... ... ... 0-74 



Thickness „ : „ ... ... ... ... 0'63 



This species only differs from T. globnlosa by its somewhat greater length and 

 by the punctuations of the surface being larger and more distant ; it may 

 possibly be only a variety of the former, but there are only a few specimens 

 of each form as yet known, and these do not allow a very critical comparison ; 

 they also do not occur on the same geological horizon. The posterior side of the 

 present form is considerably longer than the anterior, and somewhat turned up- 

 wards at the termination ; both ends are rounded. The shell is also very slightly 



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