T. H. Withers — Cirripedes from the Chalk. 



21 



Y. — Some Cirripedes from the Chalk of Salisbury, "Wilts. 



By Thomas H. Withers, F.G.S. 



I LTHOUGH the remains of pedunculated Cirripedes are com- 

 xJl paratively rare in the Chalk of England, especially in its lower 

 zones, one can, by careful collecting extended over a number of years, 

 get together a fair series of the detached valves of the capitulum. 

 Thus a very fine series of Cirripede remains has been accumulated 

 by Dr. H. P. Blackmore, F.G.S., from the upper zones of the Chalk 

 near Salisbury. This collection, which, through the kindness of 

 Dr. Blackmore, I have lately had the opportunity of examining, is 

 especially rich in the valves of Scalpellum fossula, Darwin, and 

 , S. maximum (J. de C. Sowerby). It is, of course, only on extremely 

 rare occasions that the valves of the capitulum are found associated, 

 but Dr. Blackmore has been fortunate enough to obtain part of the 



SDB- ROSTRUM. 



Fig. 1. Restoration of Scalpellum fossula, Darwin. (After Darwin.) To show 

 position of valves, and the more primitive types of carina and scutum in 

 which the umbo is apical, and the growth of the valves consequently directed 

 downwards. Senonian: Norwich. 



Fig. 2. Restoration of Scalpellum magnum, Darwin. (After Darwin.) To show 

 the more advanced types of carina and scutum in which the umbo is sub- 

 central, and the growth of the valves directed in opposite directions. 

 Coralline Crag : England. 



■ capitulum of a form probably referable to Pollicipes glaber (F. A. 

 Boemer), a few associated valves of S. maximum, and a really beautiful 

 example of S. fossula with all the valves of the capitulum in position, 

 as well as a few of the calcined plates of the peduncle. These 

 specimens I hope to be able to describe and figure at some future time. 

 The present paper contains descriptions of two species of Scalpellum, 

 of which one is new, one new species of Pollicipes, and one of Loricula, 

 all in the collection of Dr. Blackmore. Two of these, Scalpellum 

 JDarwinianum, Bosquet, and Loricula expansa, sp. nov., are of great 

 interest from both a stratigraphical and phylogenetic standpoint. 



In the earlier and more primitive forms of Scalpellum, the umbo of 

 two of the typical valves of the capitulum (the carina and scutum) is 

 apical, and the growth of the valves is consequently in one direction. 



