THE BURROWING BARNACLES (CIRRIPEDIA: ACROTHORACICA) 137 



1.0 - 



0^ 



2.5- 



2.0- 



I 1.5 H 



,0.5- 



\. ^ . ^ 



I ' ' ' ' I ' ' ' ' I ' ' ' ' I 



0.5 1.0 1.5 2.0 



LENGTH. MM. 



■ ■ ' I ' ' ' ' I ' 

 2.5 3.0 





^ / 



* B 

 V O 



• E 



^ I I 



0.5 



I ' ' I ' I ' ' ' ' I ' 



1.0 1.5 2.0 



APERTURE LENGTH, MM. 



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2.5 3.0 



Figure 38. — Simonizapfes davenporti, new species: a, burrow aperture in Gryphaea mutabilis, 

 from New Jersey, surface view; b, burrow aperture length versus width in three genera of 

 shells; c, burrow aperture length versus burrow depth in three genera of shells. 



