202 Chatwin: Cretaceous Lamellibranchia of Yorkshire. 
is quite a common and characteristic fossil of the same 
horizon in the South of England. 
Much work has been done from time to time in subdividing 
the Pectinide, and P. orbicularis, J. Sowerby, from the bruns- 
vicensis-zone at Speeton is now referred to under. the genus 
Syncyclonema. Under Camptonectes are included Pecten 
cinctus, J. Sowerby, from the jaculum-zone of Speeton, and 
P. striato-punctatus, Roemer, from the lateralis and jaculum 
zones. Pecten cretosus Defrance, from the Chalk, is not 
recorded from Yorkshire in the present monograph, but it 
is mentioned in Rowe and Sherborn’s list (Proc. Geol. Assoc., vol. 
18, p. 295, 1904) ; it now belongs to Bolten’s genus Chlamys. 
The names of Plagiostoma hopert, Mantell, from the quad- 
ratus-zone of the Coast, of Lima subrigida, Roemer, from the 
Upper Speeton Clay, and of Perna muileti, Deshayes, from 
the Lower Speeton Clay, still hold good, but Lima elongata, 
Roemer, from Speeton, should now be referred to as Lima 
(Acesta) longa, Roemer. In the lateralis-zone of Speeton, 
examples of a Lima like granulatissima have been found ; 
and these probably belong to the genus Limea. Further Limas 
from Speeton include the form described by J. Sowerby as 
Modiola elongata, but which now is to be called Lima (Man- 
tellum) parallela; and the casts occurring in the jaculum-zone 
are probably the same as Plagiostoma elongata, to which the 
new name Mantellum gaultina, Woods, has been applied. 
Two of the Avicule described by Roemer have been recorded 
from the Yorkshire Cretaceous. A. macroptera (referred to by 
Lamplugh as A. inequivalvis)=Pteria (Oxytoma) cornuelianum 
Orbigny, from the lateralis-zone of Speeton, and A. lineata= 
P.(O.) tenuicostata, Roemer sp., from the quadratus-zone of 
Sewerby and Ruston Parva. The form described by Fischer 
de Waldheim as Inoceramus concentricus, which is the same as. 
that for which Phillips used the Bean MS. name Perna imbri- 
catus, should now be called Aucella keyserlingiana, Trautschold. 
It comes from the jaculum-zone of Speeton. J. de C. Sowerby’s. 
Avicula grypheoides, from the Red Limestone and varians- 
zone of Speeton, belongs to the genus Awcellina ; while Phillips’ 
Pinna gracilis, of which the type cannot be found, is probably 
the same as P. vobinaldina, Orbigny, a name that has priority. 
Three forms of Astarte have been found at Speeton. A. 
senecta, a form from the lateralis-zone, has been established 
under Bean’s MS. name. Another form, resembling A. 
senecta, but of which only the right valve is known, has been 
called Astarte sp. The third, now called A. (Eriphyla) levis, 
is the same as described by Phillips as Crassina levis. The 
Cyprinide and the Cardiide are not numerous, the families 
being respectively represented only by Cyprina sp., and Proto- 
cardia sp. 
Naturalist, 
