6 



PROCEEDINGS OF THE NATIONAL MUSEUM 

 Morphological Variation 



Shape of pereonite 1. — All of the oceanic specimens had the 

 more sharply produced pereonite 1 described by Thorsteinson for 

 C. kincaidi. In profile it is very sharp and high in small specimens 



Figure 4. — Profiles of pereonite 1 of three populations of Cyphocaris challengeri, showing 



variation with age. 



and as the anunal grows the process becomes more rounded and 

 lower. A series of profiles of pereonite 1 from representative growth 

 stages is shown in figure 4. In a similar series from inshore popu- 

 lations collected in the Puget Sound region, pereonite 1 is also more 

 produced in small specimens, but it does not approach the condition 

 in oceanic specimens. Specimens from Lynn Canal and Revillagigedo 



