4 



30 CEETACEOUS PELECYPODA 



21-22.--^ Gast. americam, Gabb, (Jour. Phil. Acad., 2nd Ser., vol. iv, p. 393, pi. 68, %, 20), 

 is to all appearance a true Gastrochcena, and the same must be said of the South Indian FisUdana 

 aspergilloides ^Forbes. 



The CLAVAGELLINjE have representatives in cretaceous deposits, belonging to the genera 

 Clavagella and Stirpulina, 



23-26. — Pictet (loc. cit., p. 6,) enumerates four European cretaceous species of Clavagella, 

 C. cretaeea, d'Orb., and C. clavata [? Tereclina clavata, Rom., sp.), may either belong to Clava- 

 gella or to Stirpulina ; in neither case do the specimens seem to have been sufficiently well preserved. 

 CI. Cenomaniana and CL Ligeriensis, d^Orb., are known only by their names. 



27-28.-— Miiller (Suppl. to Monograph der Petrsef. der Aachner Kreidef., 1859, p. 17,) 

 described two species, CL elegans, which is a Stirpulina, while the other, CI. divaricata, is very 

 doubtful, being based upon a single valve which is rather different from the usual type of Clavagella. 



29. — CL cornigera, Schafh. Siid-Bayerns ( Leth. geogn., 1863, p. 179), is apparently a 

 Stirpulina, although the figure does not exhibit any difference in the valves ; it would seem as if 

 both valves were free, or both grown together with the tube j in the latter case the species must be 

 transferred to Brechites. 



30. — CL exigua, Zittel, (Denksch. Akad., Wien, vol. xxiv, 1865, pt. 2, p. 107,) is from the 

 Alpine Gosau-deposits. 



31. — From America only one species is known, CL armata, Mort., which is very similar to the 

 last, and probably a Stirpulina. 



32. — CL semisulcata, Forbes, will be described subsequently. 



33. — The only notice of a species possibly belonging to the BMI^CIIITINjE is by Rominger in 

 Eronn''s Jahrbuch f. Min. for 1847, p. 659, where the author mentions a new species, Aspergillum 

 cretaceum, from the Turonien beds of the county of Glatz. No further notice beyond the name 

 has been published; probably the species is the same as the one described by Schafhseutl, noted 

 above. 



Thus on comparing the species of gastrocejENidm, represented in cretaceous 

 rocks, we find that more than two-thirds belong to the gastroce^ninje, somewhat 

 less than a third to the clavagellin^, while the occurrence of ^i^^c^JiYiv^^ is doubt- 

 ful, and in any case their number would be the smallest. The gastrochjeninje are 

 already known from the Trias and gradually increase up to the present time ; the 

 cLAVAGELLiNu^, howeYcr, havc not as yet been met in strata older than the creta- 

 ceous. 



V. EOCELLAEIA, FL de Bell, 1802, (see p. 26), 



1. EOCELLARIA GUTTULA, Stollczha, PL I, Kg. 7. 



i2. testa vahis ovato-elongatis, convexiusculis, sublwvigatis, antice acutiuscuUs, 

 postice siib-truncatis, valde incequilateralibus ; hiatu antico magno, lato, posticefere ad 

 dimidium longitudinis extenso ; tuhis hrevibus, regulariter omtis, antice rotmidatis, 

 postice rapide contractis, atque breviter prolong atis. 



The tubes formed by this species are very characteristic ; they are regularly 

 ovate, inflated, but at the posterior end rapidly attenuated and shortly produced. 

 The valves are large, high, posteriorly truncate, and the gape reaches on the ventral 

 side to only about half the length of the shell. 



Locality,— Odium, and Moraviatoor ; generally found boring in oyster shells. 



Formation, — Ootatoor group. 



