76 CEETACEOUS PELEOYPODA 



Fl. intermpta, Ph. consolrina, Ph. dilatata, Keyserling, Ph. BorrissdJcii, Ph. navicnlaris, 

 (CARDlss.); — Ph. costifera, Ph. taurica, the last two species have an internal ridge running ob- 

 liquely from the beaks towards the periphery, like in most of the PHOLADIDjE. 



153-154. — Ph. Darrassi (not Barrassi as entered by Pictet and Campiche) aod Mo Hi of 

 Coquand are two species which rather belong to Poromya or Pleuromya than to Pholadomya. 

 A few species may be added from Africa, if any of those now considered Jurassic deposits, but pro- 

 nounced by Krauss to be cretaceous, should turn out to be of the latter age. 



155-164.— Meek (Smith. Misc. Coll., No. 177,) quotes from North America Homomya alta, 

 (may also be a Poromya), Ph. elegantula, occidentalism papyracea, suhventricosa, suhelongata, tenua, 

 ( — is^),iexana,tippana,^n^ Ph. ( Cymella) undata ; he^idiQ^ Ph. pedemali^ and uynhonata, Eom., 

 which have already been mentioned. 



165-166. — Goniomya americana and horealis, (ibid.). 



167-172. — Gabb (Pal. Calif, i, p. 152, &c.,) describes Ph. Brewerii (multic), — Ph. nasufa, 

 (CARDISS.), — Rom. concentricaj Gabb, Arcomya undulata, Ple2iromya papyracea, and Ph. Orego- 

 nensis, Gabb, (PaL Calif, ii, p. 235-236). 



173. — Ph. sanctl'SahcB, Homer, (Texas, Cardium id., p. 48). 



ll^.—Pachymya Austinensis, Shumard, Trans. Acad., St. Louis, I860, p. 604. 



175-176. — Ph. syriaca and decisa, Con. (Off. Eeport in Lynch's Exped, to Palestine; see also 

 Fraas in Wiirtbg. Nat. Jahreshefte, xxiii, p. 238). 



177-180. — In the South Indian cretaceous deposits four species occur. Ph. caudata is identical 

 with the European species; another was named by Forbes connectajis ; the two others are new, 

 Ph. radiatula and pedisulcata ; the first of these belongs to the type of Ph. rodrata ; the second is 

 a peculiar elongated form with the front sides sulcated, and gaping. 



Thus, we observe from this very brief review that the cretaceous beds possess 

 nearly as great a variety of generic types of the Anatinid^ as do the jnrassics. 

 The genera which are sufficiently well known are Thracia, Corimya^ and very pro- 

 bably Feri^loma and Asthenothcerus ; Analina (with Cercomya, Anatimya, Flecto- 

 mya^ and perhaps Flatymya) ; Ceromya, Goniomya, Fholadomya, Myacites, and very 

 probably JELomomya and Fleuromya. Several species described as Fholadomya, but 

 most likely belonging to Poromya, still have to be separated from the great number 

 of true Fholadomyce, 



COEIMYA, Agassiz, 1842 (see p. 63). 



y/ 1. CoRiMYA Oldhamiana, StoUczka, PL II, Pigs. 14-15. 



Cor. testa oUonga, compressimcula, tenui, posiice anguste hianti, inceqtiilaterali, 

 parte postica breviori quam antica ad marginem superiorem multo compressa ; 

 utrinque lente rotundata ; umhonibus p^^ominulis, postice versus cu?'vatis, in parte 

 posteriori distincte fissuratis : fissura oUiqua, ejusdem marginihus inversis tumes- 

 centihus, postice sed juxta hanc fissuram costa crassiuscida dimidio altitiidinis testce 

 equante sita ; superjicie concentrice striata ac tineis interruptis radiantihus per- 

 tenuibus induta ; vatva sinistra panto majori quam dextra. 



Height of shell : its length ... ... ... ... 0-51 



Thickness „ : „ ... .,, ... ... 0*26 



The external calcareous layer of the shell which is very finely concentrically 

 striated is thicker than the inner nacreous layer, on which, however, some short 



