ON A REMARKABLE NEW CIRRIPEDE. 945 
PAPERS. 
50. A remarkable new Cirripede from the Chalk of Surre 
I Ng 
and Hertfordshire. By THomas H. Wiruers, F.G.S.* 
[Received May 27, 1914: Read October 27, 1914.] 
(Plate I.¢ and Text-figure 1.) 
INDEX. Page - 
DnGrocu cho nme een eer ct en Meee dA oe ed eee apk OAS 
SUIPDKCH TOURS ON? JEVAOAA POMC cen aceaseensinenees eobbadesd seebacacaneel i a Fal0 
Evolution of the Verrucide ............. 951 
Distribution (Geological), Cretaceous at Tivelens ere 
verruca, Scalpellum (sensu lato) .....0.........00.2..... 946, 952 
Proverruca vineulum, gen. et sp. 0. ......... 946 
Proverruca compared with Verruca fail. Calantivn 
(Scaliiclieras) lteter eA oleae: 950) 
Seal pellumwiminreumer SP. Ws... 122 sectecce see eeseee-te--s.au--- 902 
Among some Cirripede remains recently collected from the 
Chalk of | Surrey are a number of isolated valves, which, together 
with a remarkably complete specimen of the same species from 
the Chalk of Watford, Hertfordshire, throw much light on the 
evolution of the sessile Cirripedes of the family Verrucide. They 
constitute, in fact, the ‘“ missing link” between the pedunculate 
Cirripedes of the family Pollicipedide and the sessile asym- 
metrical Cirripedes of the family Verrucide. 
The valves from Surrey were obtained by me from a mass of 
unusually soft Chalk found by Mr. C. P. Chatwin in the Slines 
Oak Pit, Worms Heath, near Woldingham, and to judge from the 
single example of Alicraster precursor collected from the same 
horizon, the chalk appears to be in the upper part of the zone 
of Micraster cor-testudinarium. This is the zone to which it has 
‘been assigned by Mr. G. W. Young f. 
Much difficulty was experienced in studying these valves, for 
although they were all somewhat similar in external ornament, 
the scuta and terga differed so much in structure that it was 
apparent that more than one species was represented. What was 
evident, however, was that certain of the scuta and terga, appar- 
ently of the same species, were extremely convex tr. ansversely and 
formed a semicircle when placed in position. This fact suggested 
to me the possibility of their belonging to a new form of sessile 
Cirripede, since if the capitulum were completed it would approach 
more closely to radial symmetry than is the case in an ordinary 
* Communicated by Dr. W. T. Carman, F.Z.S. 
+ For explanation of the Plate see p. 953. 
~ 1905. “Phe Chalk Area of North-east Surrey,’ Proc. Geol. Assoc. London, 
vol. xix. p. 208 (pit 127a). 
Proc. Zoou, Soc.—i914, No. LXIV. 64 
