12 
CRETACEOUS ECHINODERMATA 
3. IIemiasteii tubekosus, Sloliccka. PL I, Eigs. 3 — 0. 
U. testa amhitu undulate cordiformi, postice amjnste truncata, modice, alta, 
siqv'a convexiuscida, antice convexe declici, postice panto alliore, inf evne fere plana, 
confertim tnherculata, tuhcrculis in regions supera, fasciola peripelali dislincta 
minntissimeqne grannlata circumdatk, mnlto majorihus atque distantioribns quani ad 
periplieriani, sed Us in regione antero laterali infcra sitis fere cequalihus ; regione post- 
orali elongate triangulari, amhulacris minute granulosis marginala, tubercuUs prope 
aperturam majoribus, posticeque minoribus, densis ornata ; talmlis omnibus testce 
convexiuscidis ; ambulacris valde inccquaUbus, poslero lateralibus dimidio antero- 
lateralium cequantibus, sulco anteriore ceteris minus jyrof undo ; fasciola magna, antice 
usque ad periplicriam cxtensa, dimidio postico rapiide contracta. 
This is a very well marked species, readily distinguished by the much greater 
size of the tubercles on tlic upper surface within the peripetal fasciole, than 
at the periphery ; on the anterior portion of the lower surface they arc largest ; on 
the triangular, somewhat elevated, post-oral space anteriorly large, posteriorly 
smaller and very closely arranged. The test is moderately elevated, cordate, with a 
slightly undulating outline, all the amhulacral and inter-ambulacral plates being 
slightly convex ; posterior half slightly liiglier and narrowly truncate at the end. 
All the amhulacral plates arc perforated, the posterior on the lower side much 
elongated and only finely granular. 
The anterior sulcus is of almost equal rvidth throughout, hut shallower than 
the other ambulacra, the postero-laterals are half the length of the antcro-laterals, 
and both are truncate at the end ; the latter diverge under an angle of 100 degrees, 
and each is composed of about 3G pairs of pores ; the postero-laterals under an 
angle of 70 degrees, and there arc about 20 pores in each series. Each pair of 
pores is separated from the next by a fine granulated ridge, lining a slightly broader 
furrow; the pores are rather close together, but become more widely separated 
towards the ends of the petals. 
The posterior half of the fasciole is rapidly contracted; anteriorly it reaches 
very nearly to the periphery of the test. 
Localities. — Karapaudy and South-East of Mulloor, in coarse sandstone, very 
common ; Olapaudy, in a fei’ruginous oolitic rock, less common ; a single specimen 
is from a grey fine-grained sandstone, North of Alundanapooram. This last locality 
lies within the geographical limit of the Trichinopoly group, but the preservation 
of the specimen is exactly the same as those from the Arrialoor beds. 
Formation . — Arrialoor, and (?) Trichinopoly group. 
( 82 ) 
