8& CRETACEOUS PELECYPODA 



55.56. — P. acuminata ( ? Ilomomi/a) and P. ,«^«a//« are described by Schafha-'utl from the 

 same beds in which cretaceous fossils according to him also occur, but the exact position of the fossil 

 is unknown (see Siid-Bayern's Leth. Geog., 1863, p. 174). 



57-58. — p. rustica and fi-equens, Zittel, are from the Alpine Gosau firmation (Denkseh. Akad., 

 Wien, 1865, XXIV, pt. II, p. 110, &c.). The first in form somewhat resembles Sowerby'a 

 l/eviuscula, the second may be, as already stat<;d, a Poromya. 



Eichwald (Leth. Ross., XI, 1H07, p. 781, &c.,) also mentions from the cretaceous beds 

 of Russia P. regularis and striata [=sHbstriala). 



59. — Bosquet (Staring's bod. v. Nederland, II. doel,) tpiotes, besides P. Goltl/ussi and 

 Esmarki, a P. Santi-Petri ; I am not acquainted with that species. 



60-67.— Meek (Smith. Mis. Coll., No. 177,) quotes from North America P. decisa, Netcberr/i, 

 occidentalis , suljplicata, sutjparallela, texana, Tuomei/i ? Pachi/mj/a amtenensis , which is more probably 

 a species of the Myiidje, (see p. 67), and Pan. concentrica, Gabb , from the Californiun cretaceous 

 de'posits; this last is, however, subsequently (Pal. Calif. II) referred by its author to Uomomi/a. 



P. (lecisa of Conrad has been referred by Gabb to Cyrtodaria (= Glycimeri.i) , but unless 

 Conrad's figure and descriptimi is very incorrect the species cannot belong to that genus. 



68. — Conrad describes (in OfiSc. Rep. of Lyuch's expedition to Palestine) P. peclorosa &x\A 

 orientalis, which I only know by name and cannot say whetlier the second one is considered identical 

 with the Indian species. 



69. — P. orientalis, Forbes, is the only species which occurs in Southern India. 



70. — P. Nagorzanyensis, Favre, (Desc. Moll. foss. de Lemberg, 1869, p. 104, pi. xi, fig. 9), is 

 from the upper cretaceous beds of Galicia. 



SAXICAVA, m. d. Bell, 1822, (see p. 84). 



1. Saxicava tenella, Stoliczka, PI. XVI, Figs. 20-24. 



Sax. testa transversaliter elongate-ovata, inceqtiitaterali, pertenui, umbonibus 

 minutis suh-anticls, in svperficie striis minutis incrementi instructa ; valvulis sub- 

 incBqiiaUhns, moderate tumldis, dextra paulo majori ; cai^lo in valoula dextra 

 dentibus diiobus quorum superior minutiis, in val. siiuntra dente unico instructus, 

 nyviphis parvulis. 



Height of shell : its length ... ... ... ... Oo8 



Thickness „ : „ ... •■■ •■■ •■• 0-22 



The shell of this species is remarkably thin, sometimes almost hyaline, very 

 finely concentrically striated ; the beaks are prominent and situated at nearly one- 

 third of the total length from the anterior margin ; the right valve is a little larger 

 than the left, as, for instance, in adult specimens of the recent S. similis, Desh. ; 

 the hinge in the right valve has two teeth, one stronger below and a little in front of 

 the beak, and one smaller above and anterior to it, the latter being, strictly speaking, 

 only a slight projection of the shell margin ; the left valve has one small tooth 

 below the beak ; the nymphse are small, but more distinct in the left than in the 

 right valve. 



Locality. — North of Odium, not uncommon in a dai-k brown somewhat sandy 

 liniestone. 



Formation. — Ootatoor group. 



