Dr. lleid on a new sjjecies of Actinia. 35 



bands of a faint reddish brown colour and adhering along their 

 edges, radiate inwards from the circumference of the disc, con- 

 verge at its centre, and prolong themselves upwards to form the 

 mouth, or rather the lips. The margin of the lips is surrounded 

 by twelve small processes, six of which are very minute ; these 

 processes are of a triangular form and of an orange colour, except 

 at the edges, which are translucent. This prolonged mouth did 

 not always occupy the centre of the disc, but could be directed 

 towards any part of the margin. 



The external sac sent strong partitions inwards, the position of 

 which was marked by the longitudinal lines on its outer surface, 

 and in the interstices of these partitions the ovaries were placed. 

 This animal in many respects closely resembles the Iluanthos 

 /Sco/fcMS of Professor E. Forbes*, and the chief difference between 

 them is found in the structure of the mouth. 



EXPLANATION OF PLATES V. and VI. 

 Plate V. 



Figs. 1, 2, 3, 4 and 5. Representations of the more cohimon forms assumed 

 by the larvae. 



Fig. 6. A larva slit open and stretched out to show the four vertical canals, 

 and the manner in which they terminate in the circular canal : 

 a, extensible lips ; 6, circular canal ; c, four vertical canals ; d, ten- 

 tacula considerably shortened by their contraction. 



Fig. 7. Transverse section of the body of a larva to show the manner in 

 which the four vertical canals are formed : a, vertical canals. 



Fig. 8 Filiferous capsule entire. 



Fig. 9. Filiferous capsule burst and the spiral filament uncoiled. 



Fig. 10. Larva throwing out stolons, from one of which a bud is springing. 



Fig. 1 1. Larva having several buds growing from its surface. 



Fig. 12. Upper half of a larva eight days after it had been cut across. 



Fig. 13. One of the forms assumed by some of the larvae. 



Plate VL 



Fig. 14. Larva in the process of splitting into young Medusae. 



Fig. 15. Lower surface of one of the young Medusae after its separation 

 from a larva : a, one of the four bifid processes in the stomach ; 

 c, ocellus. 



Fig. 16. Greatly enlarged view of one of the bifid processes in the stomach. 



Fig. 17. Greatly enlarged view of one of the eight marginal rays or lobes : 

 a, ocellus. 



Fig. 18. Greatly enlarged view of the crystals in apex of ocellus. 



Fig. 19. Two of the nucleated cells and several of the nuclei that enter so 

 abundantly into the structure of the internal layer, as seen when a 

 portion of this layer is detached. 



Fig, 20. Small portion of a tentaculum, highly magnified, to exhibit the fili- 

 ferous capsules adhering to its outer surface. 



Fig. 21. Representation o^ Actinia cylindrica of the natural size. 



Fig. 22. Oral surface of one of the tentacula. 



in the examination of the more minute structures figured above, a one- 

 eighth of an inch object-glass made by Powell and Leland, and a one-fourth 



of an inch object-glass by Smith and Beck, were employed. 



* Annals of Natural History, vol. v. p. 180. 



3* 



