142 REPORT OF NEW JERSEY STATE MUSEUM. 



monograph. These have only been modified to allow compre- 

 hension in variation, etc. The keys are mostly made up from 

 those given by Dr. Henry A. Pilsbry in his studies of this 

 interesting group. 



Sub-Order EUCIRRIPEDIA. 



Cirripedia with carapace, consisting either of capitulum on 

 peduncle or an operculated shell with basis. Body formed of 

 six thoracic segments, generally furnished w'ith six pairs of 

 cirri. Abdomen rudimentary, often with caudal appendages. 

 Mouth with labrum not capable of independent movements. 

 Larva firstly uniocular with three pairs of legs, lastly binocular 

 with six pairs of thoracic legs. 



This group comprises three families. These are the sessile 

 forms or Balanidcc, the off-shore Verrucidcr of our waters, and 

 the Lepadida; or stalked forms. 



The other forms, which undergo extreme degeneration are 

 grouped under another sub-order, the Rhizocephala. 



Key to the fainilies. 



a. Body with stalk, and more or less flexible. LEpadid^ 



aa. Body sessile, without stalk. bal.\nid^ 



Family LEPADID.E. 



Tlie Goose Barnacles. 



Body stalked, or with peduncle, flexible, and furnished with 

 muscles. Scuta with abductor muscle only, and other valves, 

 when present, not united into an immovable ring. 



These animals are distributed over the whole world, most of 

 them; being found attached to floating objects or other animals 

 capable of changing their position. The others live attached to 

 fixed organic or inorganic bodies. 



