82 
CRETACEOUS ECHIXODEEMATA 
form of the test also appears to he somc-what more elongated, hut this is not very 
distinctly seen in the unique, slightly injured specimen. 
The apex has a very large madreporiform plate, which is, like the two posterior 
genital plates, largely perforated, while the perforation in the left anterior 
genital is very much smaller. All the petala are conspicuously contracted towards 
their ends, and the outer pores in each series are a trifle more transversely elongated 
than the inner ones, hut there is no distinct groove traceable between the two pores 
of each pair. 
Morton’s C. ccquoreus ( apud D’Orbigny) is another very elosely allied 
species, but it differs from the Indian fossil by having the apex and the aj)erture 
more central. 
Localllij. — Xear Odium, in a brownish earthy limestone. 
Formation. — Ootatoor group. 
4. Cassidulus ciiASSus, StoUczJca. PI. V, Eigs. 13 — 14. 
C. testa crassa, ovata, antlce siih-rotit ndata , jjostice rwpide contractu atqiie an- 
guste sub-truncata, modice alta, supra fere uniforme conrexiuscida, minute sed den- 
sissime tubei'culifera, regione post-apicoli piaidulum altiore, terminationem posticam 
versus declivi ; ambitu sub-i'otunduto ; facie inferiore planata, circa aperturam paxdo 
depressa, regione mediana subrugosa, gramdifera, laterali crassius tubercutata ; 
apice aperturaque eccentricis, paulum antice sitis : primo tabidis genitaUbus tribus 
aperte perforatis atque quarta sinistra antica minime perforata coniposito, tubulis 
ocidaribus vix distinguendis ; petalis ad terminationcs vix contractis, antico longis- 
simo, circa ‘64i jmros in una serie gerente, cceteris circiter tertiam partem longitudinis 
amb. autici brevioribus, inter se fere cequulibus, quoque circiter Its poros in una serie 
gerente, poris externis hi. quoque ordine paido longioribus quam internis, sed non jugatis ; 
ano ad summum sulci analis, fere verticalis, dhnidium altitudinis testis vix superantis , 
sito, mediocri, verticaliter ovato ; apertura pentagona, lobis quinque tubercidiformibus 
crassis cirenmdata, pjhgllodiis late ovatis, qmris internis paucioribus quam externis. 
Specimims maximi long. 32, lat. 21, altit. 17 min. 
The test is remarkably strong and thick, as compared with the size of this 
species, Avhich is readily distinguished from other species by its peculiarly ovate 
shape, with an obtusely rounded periphery, being rather rapidly contracted posterioily 
and narrowly subtruncate at the end ; the upper convexity is almost uniform, the 
greatest height being a little behind the apex, but from there the surface slopes 
gradually towards the anal slit, which is slightly inclined or nearly vertical. The 
anterior left genital plate is very small and scarcely perforated, while the three 
others possess large openings. The anterior ambulacrum is nearly one-tbird longer 
than any of the others, which arc very nearly equal among themselves, and none 
of them is contracted in any marked manner towards its end. 
( 102 ) 
