Notes from Biological Laboratory, Melh. Univ. 113 



touch of crimson lake ; and the long, slender tentacles are 

 pale, dull pink. The species is one of the Discom.edusce, and 

 belongs apparently to Hseckel's genus Desmonetna. 



I have given this brief description of the Medusa in the 

 hope that local naturalists may be induced to search for the 

 species and its interesting parasites. 



The largest of the three Actinian larvaa, all of winch were 

 obtained from the same specimen, was attached by its own 

 oral surface to one of the oral arms of the Medusa. The 

 position of the two smaller ones is a little doubtful — they 

 were only observed after the animal had been preserved in 

 spirit. 



I will describe the three parasites in order, commencing 

 with the youngest : — 



(a) The youngest example is approximately hemispherical 

 in shape, and the diameter of the oral disk is about 3 mm. 

 after preservation in spirit. The surface of the column is 

 marked by only a few transverse and longitudinal furrows. 

 No terminal pore was visible under the dissecting microscope, 

 and it may be pretty confidently asserted that none exists. 

 Twelve tentacles are already present as short, thick, trans- 

 lucent outgrowths around the margin of the disk. Within 

 these, there is an inner circle of twelve cushion-like swellings, 

 apparently produced by division of each tentacular out- 

 growth into an inner and an outer lobe — the outer lobe 

 forming the true tentacle, and the inner lobe the cushion- 

 like swelling. Some of the cushion-like swellings are not 

 yet completely marked out. The mouth is in the centre of 

 the oral disk, and furi'ows radiate towards it from between 

 the tentacular lobes. Transverse sections demonstrate the 

 important fact that twelve mesenteries are already present. 

 They also show that the longitudinal furrows on the outer 

 surface of the column correspond in position to the insertion 

 of the mesenteries. 



(h) The next s])ecimen is rather more advanced in 

 development. The general shape is still hemispherical, and 

 the diameter of the disk has increased only slightly, to 

 about 4 mm. The transverse and longitudinal furrows on 

 the surface are more strongly developed, but this is probably 

 in part, though not entirely, due to the action of the 

 reagents employed. The twelve tentacles have elongated 

 somewhat and become more conical, and the twelve cushion- 

 like outgrowths on the disk inside them are very well 

 formed. 



