[Proc. Koy. Soc. Victoria, 35 (N.S.), Pt. II., 1923.] 



Art. XVIII. — The Austral Rhynchonellacea of the "Nigricans 



Series," with a special description of the new Genus 



Tegulorhynchia. 



By FREDK. chapman, A.L.S., and IRENE CRESPIN, B.A. 



(With Plates XI-XIII.j 



[Read 14th December, 1922.] 



Contents. 



I. — INTRODUCTORY. 



II. CAINOZOIC AND RECENT AUSTRAL RHYNCHONELLIDS: WITH CRITICAL 



NOTES. 

 III. DESCRIPTION OF TEGULORHYNCHIA, GEN. NOV. GENOTYPE, " Rhyn- 



chonella'* squamosa, Hutton. 

 a. — Definition. 



b. — Distinctions from Hemithyris. 

 c. — Phylogeny of the Genus. 

 d. — Variation in Time. 

 e. — Palaeogeographical Factors. 

 f. — Evidence of Bathymetrical Habitat. 



IV. DESCRIPTION OF THE SPECIES OF TEGULORHYNCHIA. 



1. — Tegulorhynchia squamosa, Hutton sp. 



2. — Tegulorhynchia coelata, T, Woods sp. 



3. — Tegulorhynchia thomsoni, sp. nov. 



4. — Tegulorhynchia antipoda, Thomson sp. 



5. — Tegulorhynchia imbricata, Buckman sp. 



6. — Tegulorhynchia coelospina, sp. nov. 



7. — Tegulorhynchia depressa, Thomson sp. 



8. — Tegulorhynchia tuhulifera, Tate sp. 



9. — Tegulorhynchia doederleini, Davidson sp. 

 10. — Tegulorhynchia nigricans, Sowerby sp. 

 11. — Tegulorhynchia pyxidata, Davidson sp. 

 12. — Tegulorhynchia sublaevis, Thomson sp. 



V. SUMMARY. 



VI. — BIBLIOGRAPHY. 



VII. EXPLANATION OF PLATES. 



I.— Introductory. 



Since the phylogenetic relationships of the Cainozoic rhynchonel- 

 lids belonging to the " Hemithyris nigricans series " of Buckman^, of 

 the Australasian (Southern Victoria and New Zealand) and other con- 



1. Buckman, 1910, p. 13. 



