INTRODUCTION. 9 
NOMENCLATURE OF THE VALVES. 
Figure I. 
CAPITULUM. 

Figure II. Figure III. 
Scutum of PoLLIcIPEs. | oa ANS Tergum of POLLICIPEs. 
Apex. 
Apex. 



| SANA Ne margin. 
Occludent Tergo- | % HN RVG 
margin. lateral ! Scutum, “p MA NG 
margin. % ~ Bai ih 
i\\ \ Scutal Wy 
fy) ANN. margin 4 
We =e 
SS LL, HVJ “ 
Rostrum. WN BS Fr M} \ 
Basal Mi TISAI sa H/ H - Basal 
margin. i KGS A angle. 
SUNS © SSG Sub-carina. 
Sub-rostrum. Be ANSP SS 
inl Minin [Tmt NA Saeaee IK i 
Rostral Infra- Carinal 
Latus.. median Latus. 
Latus. 

PEDUNCLE. 
N.B.—In the Carina of Scalpellum, 
A is the tectum; B the parietes; C the intra-parietes. 
Whoever will refer to the published descriptions of recent and fossil Cirripedia, will 
find the utmost confusion in the names given to the several valves; thus, the valve named 
in the above woodcut, the Scutum, has been designated by various well-known naturalists as 
the “ ventral,”’ the “anterior,” the “inferior,” the “ ante-lateral,’’ and the “ latero-inferior” 
valve; the first two of these titles have, moreover, been applied to the rostrum or rostral 
valve of Sessile Cirripedes. The Tergum has been called the “ dorsal,” the “ posterior,” the 
“ superior,” the “ central,” the “terminal,” the “ postero-lateral,’” and the “ latero-superior” 
valve. The Carina has received the first two of these identical epithets, viz. the “ dorsal”’ 
and the “posterior ;” and likewise has been called the “keel-valve.” The confusion, 
however, becomes far worse, when any individual valve is described, for the very same 
margin which is anterior or inferior in the eyes of one author, is the posterior or superior 
in those of another; it has often happened to me that I have been quite unable even to 
conjecture to which margin or part of a valve an author was referrmg. Moreover, the 
length of these double titles is inconvenient. 
Hence, as I intend to describe all the recent and fossil species, I have thought myself 
b 
