404 CEETACEOUS PELEOYPODA 



entire, posterior wing agrees with Fseudo-monotis, but tlie usually characteristic 

 radiating ribs are absent, the surface being marked with thinner and thicker 

 striae of growth. It seems much more probable that the shell belongs to the 

 present genus than to Aucella, because this last never has a distinct posterior wing. 



Locality, — Raj ah- Choultry, in a conglomeratic rock, with the last named 

 species. 



Formation, — Arrialoor group. 



AUCELLA, Keyserling, 1846, (see p. 390). 



AucELLA PARVA, StoliczM, PL XXXIII, Eigs. 2-3. 



Aug. testa late et parum oblique ovata, parva, tenuis sub-lcBvigata^ striis incre- 

 menti tenuibus induta^ valva sinistra convexiore, umbone valde prominente et incur vo 

 instructa ; valva dextra planiuscula, umbone tumidulo ; utraque postice bremssime 

 et indistincter alata, v, sinistra auricula antica brevi triangulari prcedita^ infra 

 auriculam emarginata, 



A small but typical species of an Aucella, with a very thin and smooth shell. 

 The specimens are often very much compressed and deformed by pressure of the 

 surrounding rock. 



Locality, — Odium, in a light brown, soft, earthy rock. 



Formation. — Ootatoor group. 



AVICrLA, Klein, 1753, (see p. 391). 



Ayicula [Meleagrina] nitida, Eorbes, PL XXIV, Eigs. 6 — 8, and 



PL XXXVIII, Eigs. 11-12. 



1846. Amcula nitida, Forbes, Trans. Geol. Soc, Lond., vii, p. 151, — eadem auctorum. 



Avic. [Meleag.'] testa oblique sub-tetragona, equivalvi, moderate tumida, in- 

 equilaterali, margine cardinali longo, recto, margvne inferiore sub-rotundato, auriculis 

 anticis angustis, brevioribus, tumidulis, ad terminationem sub-acutis, ea vahulce dextrcB 

 ad basin vix emarginata ; auriculis posticis ab corpore testce haud distincter separatis, 

 in speciminibus junioribus postice emarginatione modica instructis fvide fig, 12, 

 tab. xxxviii,) in adultis fere rectiuscule truncatis ; superficie striis incrementi sub- 

 lamellatis, tenuissimis, distantibus, nonnunquam obsoletis tecta. 



Young shells show a small posterior emargination, the hinge-line terminating 

 in a sharp point, but in more fully grown specimens the posterior margin becomes 

 almost quite straight, as is often the case in recent Melegrince of a similar form. 

 The anterior ears are small, tumid, and pointed, that of the right valve barely 

 emarginated below, only a very narrow byssal fissure being present. The surface 

 when well preserved shows very sharp, distant striae of growth, indicating a lamellar 



