THE BURROWING BARNACLES (CIRRIPEDIA: ACROTHORACICA) 153 



pairs, as in the thoracicans) , plus the caudal appendages. The number 

 of pairs of biramous cirri are lost progressively in the genera Litho- 

 glyptes (five pairs total) and Kochlorine (four pairs total) while a 

 parallel series of genera without caudal appendages include Berndtia 

 (six pairs total), and Balanodytes (five pairs total). There is no 

 known genus with four pairs of biramous cirri without caudal ap- 

 pendages. I predict that such a genus will be found. The derivation 

 of Balanodytes from Berndtia through the loss of a terminal cirrus 

 is only a little more likely than deriving Balanodytes from Lithoglyptes 

 through the loss of the caudal appendages. The latter is quite possible, 

 however. 



The Cryptophialidae have the mouth cirri reduced to mere vestiges, 

 and a reduced number of cirri. They have a unique gizzard. 



The Trypetesidae represent a marked divergence from the above 

 families. They have uniramous cirri, no anus, and only one ventral 

 ganglion. Their reduced appendages and lack of an anus leads to 

 modified methods of feeding. Trypetesa lateralis males also lack a penis. 



The marked reduction in cirrus number, nervous structure, and 

 development of the male are seen to an even greater degree in the 

 order Rhizocephala, and a possible close relationship is to be 

 considered. 



