TY - JOUR AB - 1. The spirorbids reported earlier from Ceylon are reviewed. 2. A further collection of spirorbids from Ceylon, consisting of six new species, is described. 3. Detailed studies of the growth stages of their opercula were carried out. It was found that although the opercula of old adults appear to differ little between certain species, their growth stages show remarkable differences. 4. Keys to the Spirorbidae of Ceylon are provided. 5. The views hitherto held on the systematics of spirorbids are critically reviewed. 6. The characters hitherto used in their systematics are critically reviewed. 7. The characters of generic and specific value are categorized. 8. The spirorbids are classified according to genera and species, with definitions for the genera. New genera are proposed wherever necessary. 9. The advantages of the above classification are discussed. 10. The position of spirorbids as a group is reviewed. Characters common to the non-spirorbid Serpulidae and those which are not common to them are reviewed. 11. The differences between spirorbids and Serpulidae outnumber the similarities and are of such magnitude as to justify the separation of spirorbids into a distinct family. Hence a new family the Spirorbidae is created for this group. The family characters are defined. 12. The views hitherto expressed on the phylogeny of the Spirorbidae are reviewed. 13. A new phylogenetic scheme is proposed. 14. The advantages of this new phylogenetic scheme are discussed. 15. The geographical distribution of the Spirorbidae is discussed. 16. The pattern of distribution of the genera and species of the Spirorbidae is correlated with current knowledge on palaeozoology, palaeogeography and palaeoclimatology. A1 - Pillai, T. Gottfried JO - Ceylon Journal of Science (Biological Sciences) N1 - World Polychaeta Database (WPolyDb) IS - 2 SP - 100 EP - 172 C1 - 8(2): 100-172 TI - Studies on a collection of Spirorbids from Ceylon, together with a critical review and revision of Spirorbid systematics, and an account of their phylogeny and zoogeography UR - https://ras.biodiversity.aq/aphia.php?p=sourcedetails&id=51423 VL - 8 PY - 1970 Y2 - 2024-03-29 ER -