MEDUSA. 45 



NOTES ON THE SPECIMENS. ' SOUTHERN CROSS ' COLLECTION. 



Specimen A. This is the smallest specimen in the collection. The diameter of 

 the central disc is about 50 mm. and its height nearly 40 mm. The umbrella is 

 covered with a thick layer (about 7 mm.) of transparent jelly, and through it one can 

 see the dark brown conical-shaped stomach. At its apex there is a short (nearly 

 2 mm.) spike-shaped projection. That portion of the Medusa which lies below the 

 coronal furrow is not in good condition. The pedalia are present, but the lobes, 

 tentacles, sense organs and pigment have either completely or nearly disappeared. 

 The tentacular pedalia are about 10 mm. in width and 13-15 mm. in length (measured 

 from the coronal furrow to the base of the tentacle). The distance from the coronal 

 furrow to the distal edge of the marginal lobes is estimated at about 28 mm. The 

 specimen is too much macerated to show any gonads. 



Specimen B. The external appearance of this specimen shows that it was 

 originally placed mouth downwards in a tin can with straight sides and a flat bottom. 

 The specimen is in a fairly good state of preservation, but spoilt through having been 

 squeezed into a small can and stained with iron rust. 



The central disc is about 75 mm. in diameter, but it has lost its natural shape, as 

 the sides are straight and the top flattened. There is a thick layer (about 8 mm.) 

 of jelly, which suddenly thins out to about 1 mm. in thickness, marking the apex of 

 the umbrella. The tentacular and rhopaliar pedalia in general appearance resemble 

 closely those in Prof. Haeckel's figures of Periphylla hyacinthina (1880, Taf. 24, 

 fig. 11) and of P. mh'alrilis (1882, Plate 18, fig. 1). The tentacular pedalia are about 

 25 mm. in length and 15 mm. in width. The rhopaliar pedalia are about 33 mm. in 

 length (measured from the coronal groove to the rhopalium) and about 13 mm. in 

 width at the proximal end (next furrow), and about 8 mm. wide near the distal end. 

 They have a somewhat wedge-shaped appearance, and are longer and narrower than 

 the tentacular pedalia. The tentacles are broken off close to the pedalia, and the 

 rhopalia are entirely gone. Some of the marginal lobes appear to be in fairly good 

 condition, but have completely lost their pigment. The only conspicuous pigment left 

 below the coronal furrow is a triangular patch within the tentacular pedalia, at the 

 base of the tentacles. The distance from the coronal furrow to the distal edge of the 

 marginal lobes is about 50 mm. The gonads are in a very immature condition. They 

 are just narrow bands about 2 mm. in width. 



Specimen C. This is a large adult in alcohol, with the jelly very much shrunken 

 and of a rather opaque whitish colour. The disappearance of the dark brown pigment 

 and the thinness of the jelly, which resembles a thick tough skin, are no doubt due to 

 the method of preservation. 



The specimen has lost its natural shape, so that measurements are of little 

 scientific value, but are given to indicate the size of the specimen. The central disc 

 has a broad conical appearance, and its height is not less than 90 mm. The total 



2 B 2 



