358 1\ H. Wdhera — The Cirripede Brachylepan cretacea. 



the base of the capitulum, B. Naissmiti has a close outward 

 resemblance to the sessile Cirripede C. polymertis, but the presence 

 of these basal whorls ot valves distinguishes it from the Balanidse 

 proper {Balanus), since they have no such basal whorls of valves. 

 The discovery of the inwardly projecting ledge to the valves of 

 the basal whorls in B. Naissmiti, and their method of interlocking 

 to form a narrow shelf or platform round the base of the capitulum, 

 shows that these valves are quite different from those of C. polymerus, 

 for in that species there is a definite space bounded bj' the concave 

 inner margin of each valve. It is not quite clear from Dr. H. 

 Woodward's paper (1901) whether he definitely regarded B. Naissanti 

 as a sessile Cirripede, although he recognized its relationship to the 

 sessile forms, but the modification of the basal whorls of valves in 

 B. Naissanti to form a shelf or platform round the base of the 

 capitulum leaves little doubt in my mind as to the sessile nature of 

 this species. 



For their kindness in loaning or procuring the loan of specimens, or 

 for their assistance in connexion with this paper, I wish to express 

 my indebtedness to Dr. F. A. Bather, Dr. J. Boehm, Dr. W. T. 

 Caiman, Mr. C. P. Chatwin, Dr. P. P. C. Hoek, Dr. F. v. Huene, 

 Dr. A. W. Kowe, and Mr. C. Davies Sherborn. 



j,j^ EXPLANATION OF PLATE XX. 



1. Brachylepas Naissanti, Hebert sp. Carina, a. outer view ; a', basal 



view ; b. side view ; c. inner view. Upper Senonian (Belemnitella 

 mucronata-zone) : Litneburg, Hanover. 



2. Id. Kostrum. a. outer view ; a. basal view ; b. side view ; c. inner view. 



3. Id. Scutum, a. outer view ; a. transverse section ; b. inner view. 



4. Id. Upper latus. a. outer view ; b. inner view. 



5. Id. Tergum. a. outer view ; b. inner view. 



6. Id. One of the imbricating valves without a basalledge. (Probably from 



a position below the upper latus.) a. outer view ; b. inner view. 

 7-9. Id. Imbricating valves of the innermost whorl. a. outer view ; 

 b. inner view. (Fig. 7 probably occupied a position near the region of 

 the upper latera, and Figs. 8 and 9 either at the carina or rostral end 

 of the capitulum.) 



10. Id. An imbricating valve ; possibly of the second whorl ; the basal ledge 



is wider than in most valves, and its upturned inner extremity is 

 adapted to fix into the median notch of the valve in front of it. 



a. outer view ; b. side view ; c. basal view showing the ledge. 



11. Id. Four of the imbricating valves still attached to one another, showing 



their external arrangement and the method of interlocking of the basal 

 ledges to form the shelf or platform round the base of the capitulum. 

 (Probably from a position below the upper latera.) a. outer view; 



b. inner view. I, a valve of the innermost whorl without a basalledge ; 

 II, two valves of the second whorl with a basal ledge ; III, a valve of 

 the third whorl with a basal ledge. 



12. 13. Id. Two pairs of imbricating valves, still attached to each other. 



(Probably of the first and second whorls.) a. outer view; b. inner 

 view ; c. basal view showing the basal ledge. 



14. Id. Two imbricating valves still attached. Outer view. (Probably from 



near the region of the carina.) 



15. B. Naissanti, Hubert sp. Carina, outer view. Upper Senonian 



{B. viucronata-zone) : Meudon, France. Copy of the original figure of 

 Emarginula (?) Naissanti, Hebert, Mem. Soc. Geol. France, 2* ser., 

 vol. V, pi. xxix, tig. 10, 1855. 



