MKDU.S.E OF THK WOULD. 



This medusa was discovered by von Kennel in a fresh-water lagoon on the east coast of 

 Trinidad, south of Mayaro Point, in a cocoanut plantation. The water in which it was 

 living was apparently perfectly fresh, not being salt to the taste. The lagoon was in commun- 

 ication with the sea during the rainy season. 



Thaumantias maeotica Ostrooumoff. 



Thaumantias rnxolicu, OSTROOUMOIT, 1896, Bull. Acad. Imperiale des Sci. St. Petersbourg, bcr. 5, tome 4, p. 401, plate i, figs. 

 2, 4. S- 



Bell fuller than a hemisphere, with very thick gelatinous substance; 18 mm. wide, 10 mm. 

 high. 32 filiform, slender tentacles, twice as long as bell-diameter, with well-developed basal 



bulbs. Dark-colored ectodermal ocellus on each 

 tentacle-bulb. Velum narrow. 4 straight, slen- 

 der radial-canals. Manubnum 4-sided, prisma- 

 tic, with 4 simple lips. About half as long as 

 depth of bell-cavity. No peduncle. 4 spindle- 

 shaped gonads on the middle thirds of the 4 

 radial-canals. Sea of Azov, Russia. 



Dr. S. Lobianco of Naples kindly permitted 

 me to study some very well-preserved specimens 

 of a Thaumantias which he collected in the Bay 

 of Naples. At first I was inclined to regard these 

 as a new species, but now believe that they may 

 represent a young stage of Thaitmantias micotica. 

 I herewith present a cut (fig. 103) representing 

 the largest of Dr. Lobianco's specimens together 

 with the following description: 



Bell 4 mm. high and of about an equal width. 

 Apex evenly rounded and exumbrella smooth. 

 Gelatinous substance thick at apex, but thin at 

 bell-margin. Bell-cavity about two-thirds as 

 deep as the height of the bell. 



There are not more than 16 tentacles; the 

 number among six specimens observed by me 

 ranged from 8 to 12. The 4 perradial tentacles 

 are about twice as long as the bell-diameter, the 

 4 interradial about half this length, and the 

 adradial tentacles are not more than one-third 

 as long as the interradial. All of the tentacles 

 taper gradually to their tips and are sharply set 

 off from their globular, swollen, basal bulbs. 

 There is a black, abaxial, ectodermal ocellus 

 upon each basal bulb. The shaft of each ten- 

 tacle is regularly besprinkled with small, isolated, 

 wart-like patches of nematocyst-cells, which do 

 not form rings. 



Velum very wide. There are 4 straight- 

 edged, narrow radial-canals and a simple, slender 

 ring-canal. Manubnum small, flask-shaped, and 



I'll.. 103. Thaumantias 



with 4 simple lips. It is not more than one-fourth as long as the depth of the bell-cavity. 

 The 4 spindle-shaped gonads are developed along the 4 radial-canals from their proximal 

 thirds to their middle points. They are apparently immature. 



The collection of the Stazione Zoologica at Naples, Italy, contains six well-preserved, 

 alcoholic specimens of this medusa, which were gathered by Dr. Lobianco in the Bay of Naples. 



This medusa bears some resemblance to Thaumantias quadrata Forbes, 1848, British 

 Naked-eyed Medusae, p. 43, plate 9, fig. 2; from Loc Fyne, Scotland. In this British medusae, 

 however, there are apparently no true ocelli, the so-called ocelli of Forbes being orange- 

 colored entodermal pigment in the tentacle-bulbs. 



