ILLUSTRATIONS 



PLATES 



The West American Mollusks of the Genus Acar 



By Paul Bartsch 



Facing page 



1 . Mollusks of the genus Acar 1 



A New Marine Shell of the Genus Xenophora from Florida 



By Paul Bartsch 

 1. Xenophora longleyi, new species 2 



A Review of the Nematodes of the Genus Hastospiculum, 

 with Descriptions of Two New Species 



By B. G. Chitwood 



1. Hastospiculum seiiferum, new species, and H. spinigerum 9 



2. Hastospiculum onchocercum, new species 9 



8. Species of Hastospiculum 9 



Echinoderms from the Islands of Niuafoou and Nukualofa, 

 Tonga Archipelago, with the Description of a New Genus 

 and Two New Species 



By Austin H. Clark 



1-3. Zenocentrotus kellersi 12 



4. Zenocentrotus kellersi and Heterocentrotus trigonarius 12 



5. Zenocentrotus kellersi, Z. paradoxus, and Echinomelra oblonga 12 



6. Zenocentrotus paradoxus and Z. kellersi 12 



7. Zenocentrotus paradoxus and Echinometra oblonga 12 



8. Heterocentrotus trigonarius 12 



Upper Cretaceous Foraminifera from Trinidad 



By Joseph A. Cushman and P. W. Jarvis 



1-16. Cretaceous foraminifera from Trinidad 60 



Recent Foraminifera from the Atlantic Coast of South 



America 



By Joseph A. Cushman and Frances L. Parker 

 1-4. Recent Atlantic foraminifera from South America 24 



TX 



