414 THE GEOLOGIST. 
ON CEETAIN CRETACEOUS BEACHIOPODA. 
By E. Eay Lankester, Esq. 
In tbe Plate accompanying this paper are figured three species of 
Terebratulae, ^Yhich the writer lately obtained trom the Lower Green- 
sand beds of the Isle of Wight. Two of them are interesting as 
being entirely new to these strata in Britain, whilst the third is 
a remarkable deformity of a rare species. In Eig. 1, 2, 4, a shell is 
drawn which appears to be identical with the Terehratula Moutoniana 
of D'Orbigny, a species not uncommon in Erance, associated with 
T. sella in the Upper Neocomian and Aptian beds of that author. 
It is somewhat oval in shape, depressed and elongated ; surface 
entirely smooth. The perforate valve is rather more convex than 
the other, truncated by a foramen of moderate size ; deltidium very 
short and small. Nine specimens of this species were obtained from 
the ferruginous Greensand beds, at Dunnose Point, near Shanklin. 
This shell, on external examination, is easily distinguished from T. 
sella, which it somewhat resembles, by the absence of any biplica- 
tion on tlie frontal margin. Its internal structure proves it to belong 
to the section Waldheimia of King, which precludes all doubt as to 
its specific distinctions from T. sella. It is easily distinguished 
from Waldheimia Celtica, Morris, by its less elongated and gibbous 
outline. The specimen drawn in Eig. 5, 6, 7 is the only specimen 
of the kind which the writer has obtained. The valves are lenticular, 
beak much produced, foramen very large and circular, deltidium 
large. Mr. S. P. AYoodward is inclined, with the writer, to reg^ard 
this shell as Terebratula depressa, Lamarck [T. nerviensis of D'Ar- 
chiac), a species which has not hitherto been found, excepting in 
the Upper (?) Greensand beds of Earringdon, and in the Tourtia of 
Belgium. Since, however, two species, T. tamarindus and T. ohlonga, 
are already known as common to the strata of Shanklin and Earring- 
don, it is not surprising that T. depressa should have a similar verti- 
cal range. In Eig. 8, 9, a curious deformity of the Terebratula 
Celtica of Morris is drawn. This specimen was obtained from the 
same locality as the two former species. The beak is very much 
produced and incurved, whilst a deep furrow or groove runs along 
the median line of the perforate valve, and a corresponding eleva- 
tion marks the smaller valve. T. tamarindus, " a rare British creta- 
ceous fossil " (Dav.), was also obtained in considerable quantities, — 
Eig. 11. 
The rarity of some species and the paucity of any great variety of 
the forms of Brachiopoda in the Lower Greensand strata of England 
as compared with the large number of species characterizing the 
Continental beds usually considered as their " homotaxis," is some- 
what remarkable. There is no obvious reason why such forms as 
T. diphyoides, T. hippopus and others associated with a common 
British species, T. sella, in the Upper Neocomian or Urgonian beds 
