the Cirripede Genus Stramentum. 81 
from other cirripedes in which the capitulum and peduncle 
were not well defined. This is borne out not only by the 
postlarval development of certain recent pedunculate cirri- 
pedes, but by the forms of Archeolepas. Such a modification 
was no doubt independently developed ‘in other lines of 
CL. eee ol: 
Fig. 1.— Turrilepas wr ightianus, H. Woodward. a, shell viewed from 
back and left side. a’, transverse section of shell: m, median 
plates ; 7, lateral plates. 6, portion of shell enlarged. | (Figs. a, 
6, after Gruvel ; a’, after Withers.) 
Fig. 2. —Stramentum pulchellum, G. B. Sowerby, Jun., sp., showing mode 
of imbrication of peduncular scales. (After Gruvel.) C., carinal 
scales; C.L., carino-lateral scales; L., lateral scales ; dial 
e rostro-lateral scales; R., rostral scales. 
descent. Having arrived at the pedunculated stage, several 
forms have independently reduced the peduncle and even- 
tually assumed the sessile condition. This has been shown 
in the case of the Verrucide, and there can be no doubt that 
Ann. & Mag. N. Hist. Ser. 9. Vol. v. 6 
