XII LIST OF ILLUSTRATIONS 



Fossil and recent bryozoa of the Gulf of Mexico region 



By Ferdinand Canu and Ray S. Bassler 



Page 



1. Acanthodesia savarti Savigny Audouin, 1826. Longitudinal section, 



X 86, exhibiting the two lateral septulae 15 



2. Ciipuladria canariensis Busk, 1852, A. Vibraculum, X 85, illustrating 



articulation. B. Opercular valve and apertural sclerite, X 85 16 



3. Aplousina gigantea Canu and Bassler, 1927. Diagrammatic drawing 



of a zooecium, X 85, showing the tentacular sheath attached to 

 the opercular valve. This is fixed to an exterior thickening of the 

 ectocyst 20 



4. Levinsenella brasiliensis, Busk, 1884. Opercular valve and apertura, 



X 85, each bordered by a sclerite 26 



5. Acanthocella clypeaia, new species. A. Opercular valve, X 85. B. A 



small foraminifer, X 85, found with a zooecium. C. Cribrilina 

 iinea^a, new species, operculum, X 85 40 



6. Genus Tremog aster ina Canu, 1911. A. Tremogasterina lanceolaia, new 



species, opercular valve, X 85. B-F. T. granulata, new species. 



B. Ordinary operculum, X 85. C. Operculum with thick chitinous 

 band. D. Another form of operculum, X 85. E. Mandible, X 85. 

 F. Longitudinal section through an ovicelled specimen, X 20. The 

 zooecial wall is much calcified. The ovicell is hyperstomial, closed 



by the operculum 46 



7. Velumella aviericana, new species. A. Portion of the ectocyst, X 85, 



covering the opesium, showing the apertural structure. B. Draw- 

 ing, X 85. C. Mandible of the onychocellarium with the elevator 

 and occlusor muscles, X 85 55 



8. Opercular valves of opesiulae. A. Dacryonella typica, new species. 



Valve somewhat thickened in the middle. B. Floridinella typica, 

 new species. C, D. Floridina antiqua Smitt, 1873. E. Micropora 

 coriacea Esper, 1791 ' 58 



9. Siphonoporella dumonti, new species. A-C. Different aspects of the 



opercular valve. In A the sclerite of the valve is exactly superposed 

 on the exterioi sclerite of the ectocyst. D. The two portions of an 

 avicularian mandible. They are united by two strong lateral 

 3clerites. E. An ordinary onychocellarium, X 85 68 



10. Mollia paiellaria Smitt, 1873. Drawing of a zooecium, X 85, showing 



the apertural sclerite somewhat removed from the mural rim and 

 supported with the opercular sclerite on the two opesial condyles. _ 70 



11. Opercular. Exechonella pumicosa, new species. A. Somewhat elon- 



gated operculum, X 85, showing the axis of rotation (ar). B. • • 



Puellina floridana Smitt 1S73. A much chitinized operculum, X 85. 



C. Figularia? ampla, new species. Operculum, X 85. D. Stenopsis 

 fenestrata Smitt, 1875. Operculum X 85. E. Trypostega venusta 

 Norman. Operculum, X 85 71 



12. Genus Petraliella, new genus. A-I. Petraliella bisinuata Smitt, 1873. 



A. Operculum, X 85, with broad, chitinized marginal band. B. 

 Another operculum, X 85, with narrow marginal band. C. Another 

 form of operculum, X 85. D. Operculum, X 85, in which the 

 proximal articulation with the compensatrix is visible. E, F. G. 

 Three mandibles, X 85. H. Radicel of this species, X 85. I. 

 Petraliella marginata, new species. Operculum, X 85, with narrow 

 marginal band 79 



