8 UNITED STATES NATIONAL MUSEUM BULLETIN 296 



if present, are on the posterodorsal end of the thorax. Anterior is 

 toward the head, posterior toward the terminal cirri. 



Segmentation 



Segmentation in the Acrothoracica has been thoroughly covered 

 by Darwin (1854), Berndt (1903a), Gruvel (1905), and Utinomi 

 (1957). 



The only information that should be added here is that the occur- 

 rence of six pairs of cirri plus caudal appendage in Weltneria has 

 eliminated all doubt as to the homology of cirri between the Acro- 

 thoracica and the Thoracica. The Acrothoracica can possess the 

 same cirral complement as the Thoracica. The loss of cirri is 

 probably at the anterior end of the terminal set of cirri, as evidenced 

 by the retention of a caudal appendage in Lithoglyptes and Kochlorine, 

 with four and three pairs of terminal cirri, respectively, and the 

 tendency for the first pair of terminal cirri to be reduced. 



Common Names 



There are two words in common English usage which I would like 

 to review at this time. The first word is the common name contraction 

 of the subclass Cirripedia — should it be cirriped or cirripede? I 

 will use the former, and urge its general adoption. Dr. James A. H. 

 Murray (1893) lists the following: 



ciRRiPED-PEDE. 1828 Stark Elem. Nat. Hist. II. 121 Class IV Cirripeda 

 (MoUusca Cirrhopoda, Cuv.) 1832 Lyell Princ. Geol. II. 108. So loaded 

 with cirrhipeds, and with numerous ova, that all the upper part of its 

 shell is invisible. 1855 Gosse Marine Zool. 1. 168. The bivalve shell is 

 thrown off, and the little cirriped is seen in its true form. 1859 Darwin 

 Orig. Spec. IV (1873) 79. Cirripedes long appeared to me to present 

 ... a case of great difficulty. 



Note that Darwin is the first authority listed using the spelling 

 CIRRIPEDE. Even his geological mentor Lyell used the -ped ending! 

 Nevertheless, the speUing has changed over the years. The Shorter 

 Oxford English Dictionary on Historical Principles, edited by C. T. 

 Onions in 1933 (Oxford) also Hsts the word cirriped -pede. 



I cannot cite recent references completely because of copyright 

 requirements, but Funk and Wagnalls' Britannica World Language 

 Edition for the Encylopedia Britannica (1956) cites only one spelHng — 

 cirriped. To compound the confusion, Webster's Third New Inter- 

 national Dictionary unabridged (1961) cites it cirripede, cirriped, 



