THE BURROWING BARNACLES (CIRRIPEDIA: ACROTHORACICA) 127 

 Table 2. — Shell thicknesses at the site of Trypetesa burrows 



Trypetesa lampas in Buccinum undatum shells 



Trypetesa lateralis in Tegula funebralis 

 shells 



Trypetesa lateralis in Tegula brunnea 

 shells 



♦Average of three readings over barnacle burrow, in millimeters. 



represent one of the rami of the primitively biramous appendages. 

 The two proximal segments of the cirrus would thus correspond to the 

 standard protopod of the other species. 



Trypetesa lampas (Hancock, 1849) 



Figure 34 



(=Alcippe lampas Hancock, 1849, page 314.) Alcippe lampas gigantea Berndt, 

 1907b, page 289. 



Diagnosis: Trypetesa with "capitulum" laterally compressed, 

 perpendicular to surface of shell, with "disk" or ovigerous portion 

 dorsoventrally compressed and parallel to surface of host shell; 

 nauplius free-swimming; adult exceeding eight millimeters; bilaterally 

 symmetrical; male possesses a well-developed penis; male attaches 

 only to disk of female. 



Distribution: Reported from the sublittoral of the northern 

 Atlantic Ocean, North Sea, Mediterranean Sea, and the east coast 

 of the United States, in gastropod shells occupied by hermit crabs. 



