292 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



Rhopaloiiaria tenuis new species p. 270 



7. Portion of a colony growing on a Stropheodonta and showing a 



rather irregular growth and the attenuate fusiform shape of the 

 zooecia. 

 Hamilton formation, Thedford, Ontario. 



8. The excavated mold of a normally developed colony. 



9. The excavated mold of another colony in which the zooecia are 



crowded on account of the frequent crossing of the branches. 

 Doubtfully referred to this species. 



Hamilton formation, Alpena, Michigan. 



Rhopalonaria medialis new species p. 270 



10. Portion of a colony attached to the same shell bearing the specimen 



illustrated by figure 7. 



Hamilton formation, Thedford, Ontario. 



Rhopalonaria keokukensis new species p. 272 



11. Portion of a large colony of which the excavated mold only is pre- 



served, covering the greater part of a Zaphrentis. 



Keokuk formation, Keokuk, Iowa. , 



Plate LXVH 

 (Unless otherwise specified, the figures on this plate are X 9.) 



Alloncma botcllus (Vine) p. 281 



Fig. I. Portion of a colony attached to the dorsal valve of Leptmia rhom- 

 boid al is. 



Silurian, Island of Gotland. 



Allonema botelloides new species p. 281 



2, 3. Portions of two colonies, one growing upon Goniophyllum pyrami- 

 datum and the other upon a cyathophylloid coral. 



4. One of the vesicles of figure 3, X 18, showing a pore or pit near one 



end and the small pores of the test. 

 Silurian, Island of Gotland. 



Alloncma zcaldroiicnsc new species. p. 283 



5. Portion of a colony attached to the dorsal valve of an orthoid. 



Waldron shales, Waldron, Indiana. 



Allonema subfusiforme new species p. 283 



6. The greater part of a colony attached to Goniophyllum pyramidatum. 



7. One of the vesicles of same, X 18, showing the punctate surface. 



Silurian, Island of Gotland. 

 Allonema fusiforme (Nicholson and Etheridge, Jr.) p. 284 



8. A small part of a colony. Only one vesicle is drawn to show the 



punctse of the surface. The specimen is growing upon the porif- 

 erous side of a small Polypora. 



Hamilton formation, Alpena, Michigan. 

 Alloncma nioniliforme var. aggregatum new variety p. 282 



9. Portion of a colony growing upon a Diphyphyllum. The figure 



shows the close arrangement of the rows of vesicles. 

 Hamilton formation, Genesee county. New York. 



Alloncma f minimum new species p. 284 



10. The greater part of a colony with a young specimen of Ptychocladia 



agcllus running from the lower to the middle part of the figure. 



11. A series of vesicles of same, X 18, showing variations in form and 



the aperture-like pit in four of them. 



