150 Dr. H. Woodward — A New Cirripede from the Chalk. 



Family BEACHYLEPADIDiE, 

 BEACHYLEPAS, gen. nov., 1901. 

 Non Pyrgoma (as applied by H. "Woochv., 1865, Brit. Assoc. Eep., p. 321). 

 Valves about 100 in number ; latera of lower whorl numerous ; 

 lines of growtb directed downwards ; peduncle absent. 



Braohylepas cketacba, H. Woodw. (PI. VIII, Figs, 'ka, h.) 



Capitulum with three or four whorls of valves under the rostrum ; 

 apparently only three rows under the carina ; snb-latera larger than 

 the rest. The base on the side figured shows about fifty-four ' 

 shelly imbricated plates or scales forming eighteen vertical rows, 

 arranged partly in three and partly in four rows ; they are smaller, 

 narrower, and more pointed under the rostrum (r.), and largest and 

 broadest in the centre below the latus (see restoration, Fig. 3, I.), 

 as we see is the case in PoUicipes polymeriis (Woodcut, Fig. 1), 

 where the latera are regularly graduated in size from the upjDermost 

 to the lowest of the series. The scales under the carina (c.) are 

 larger than those beneath the rostrum (r.) ; but they are narrower 

 and more pointed than those of the lateral series (which are 

 reproduced enlarged on PI. VIII, Fig. 46). The scales have 

 a strong median ridge with lateral divaricating lines, giving the 

 free-edges a delicately plicated border. The median ridge is narrower 

 and sharper in the scales beneath the rostrum, and broadest on the 

 lateral scales. 



The carina (c.) is marked by strong vertical ridges, which ai'e 

 crossed by numerous finer encircling bands, running parallel to the 

 base, giving to both the carina and rostrum a delicate reticulated 

 surface. The walls of both are thick, and so far as can be seen 

 quite smooth on the inner surface. On the opposite aspect of the 

 carina to that drawn, the base of the capitulum is seen to be nearly 

 wholly exposed and bare, save for the presence of three of the 

 shelly scales which remain in situ adhering to the carina, the 

 largest of which is 4 mm, in length. The semicircular wall of 

 the carina measures about 17 mm. near its base around its outer 

 face, and its height on the side not covered by the sheath of 

 imbricated scales is 8^ mm. The I'ostrum is considerably smaller 

 than the carina; it measures 15mm. around the outer surface near 

 the base, and is 6 mm. in height. 



The sheath of imbricated scales covers the base of the rostrum, on 

 the side drawn in the Plate, 2 mm. deep, and extends also 2 mm. 

 below the base of the rostrum, the whole series of scales being 

 a little over 4 mm. deep. 



Viewed from above, the body-cavity, enclosed in the convexities 

 of the carina and rostrum, is seen to be oval, being 8 mm. long by 

 6 mm. broad. The walls of the capitulum are very steep, the carina, 

 which is also much the highest, seeming almost to overhang at its 

 summit. 



1 That is, 54 plates on the side figured ; if perfect, there would have been an equal 

 number on the other side, or about 108 in all. 



