634 TRANSACTIONS OF SECTION D. 



8. Report on the Occupation of a Tahlc at the Marine Laboratory. 

 Plymouth. — See Reports, p. 168. 



9. Report on the Biological Problems incidental to the Inishea Whaling 

 Station. — See Reports, p. 168. 



10. Third Report on Experiments in Inheritance. 

 See Reports, p. 169. 



11. Second Report on the Feeding Habits of British Birds. 

 See Reports, p. 169. 



MONDAY, SEPTEMBER 5. 

 Joint Meeting with Sub-section B (Agriculture). — See p. 583. 



The following Papers were read in Section D : — 



1. Some Experiments and Observations on the Colours of Insect Larvae. 

 By Professor W. Garstang, D.Sc. 



2. Comparison of the Early Stages of Vertebrates. 

 By Professor C. S. Minot. 



3. Insect Coloration and Environment. By Mark L. Sykes. 



4. A Preliminary Note on the Formation and Arrangement of the Opercular 

 Cho3tw of Sabellari. By Arnold T. Watson, F.L.S. 



Of the peculiarities of structure characteristic of the familyto which these 

 sedentary, tube-building Polychaete worms belong, the greatest interest attaches 

 to the processes called by different zoologists by the names ' Kopflappen,' 

 ' Paleeutuiiger,' ' Cephalic lobes,' or ' Peristomial lobes.' Their position in 

 relation to the head of the animal has favoured the idea of their being Cephalic 

 lobes, but such an arrangement would be exceptional, and it seems more likely 

 that they are derived from the anterior parapodin, a view which seems to be 

 supported by the present observations. These lobes, which are united dorsally 

 at their bases, but are free terminally, bear on their ventral face a series of rows 

 of tentacles, their crescent-shaped distal extremities being armed with three 

 concentric rows of palese, each of characteristic form. The armed crescents of 

 the two lobes, when drawn together, form the operculum defending the entrance 

 to the tube on retreat of the inmate. Viewed from above the exposed portions 

 of the paleas of the outer row are seen to be arranged in an imbricated manner, 

 their free ends directed outwards; the palese of the middle row also are slightly 

 imbricated, their free ends, too, being directed outwards ; the free ends of the 

 innermost row, the chsetse of which alternate in position with the last-named, 

 are directed inwards and upwards. From the exposed portions of each palea 

 an extension in the form of a long curved shaft descends at an angle of 120° or 



