44 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



LIZZIA, Forbes, 1846. 

 Lizzia elegans, nov. sp. 



Fig. 127, Plate 38. 



Specific Character''. — The bell is 3-7 mm. in height, and the gelatinous 

 substance is of moderate and nearly uniform thickness. The sides of the bell 

 are almost straight and vertical, and the top is dome-shaped. There are eight 

 groups of marginal tentacles, 4 radial and 4 interradial. Each radial group is 

 composed of 4, and each interradial of 3 tentacles. The tentacles are quite stiff 

 and curve upward, and are only about one-half as long as the bell height. 

 There is a small dark-brown ectodermal ocellus upon the under (oral) side of 

 each tentacle near the basal bulb. The velum is wide and provided with 

 strong muscles. There are 4 straight, narrow, radial canals, and a simple 

 circular vessel. There is a well-developed conical peduncle to the proboscis, 

 down which the radial canals lead in their course to the gastric sac. The 

 gastric part of the proboscis is cruciform in cross-section and pear-shaped in 

 general longitudinal contour. The mouth is a simple round opening without 

 prominent lips. The oral tentacles arise from the four radial sides of the 

 proboscis at a short distance above the mouth. Each tentacle branches dichoto- 

 mously 3 times and then each tip terminates in three small branches which are 

 covered with nematocysts. The entodermal cells of the oral tentacles are 

 chordate. The genital products are situated upon the 4 radial sides of the 

 gastric portion of the proboscis. The entoderm of the tentacle bulbs and 

 radial canals is of an intense opaque pearly-white color, often displaying a 

 tinge of pink. The entoderm of the gastric portion of the proboscis is of an 

 intense green, and the oral tentacles are pearly-pink. The intense opaque 

 color of the radial canals contrasting with the hyaline transparency of the bell 

 renders this medusa one of the most beautiful to be found at the Tortugas, 

 Florida. 



Several specimens were captured early in July, 1899. 



DISSONEMA, Haeckel, 1879. 

 Dissonema turrida, nov. sp. 



Figs. 3, 4, Plate 3. 



Specific Characters. — Adult medusa ; Figure 3. The bell is about 4 mm. in 

 height. It is blunt and cone-shaped, and there is a prominent apical projection, 

 which is hollow. There are 2 large hollow tentacles, which when expanded 

 are .3-4 times as long aa the bell height. In addition to these, there are 14 

 small solid tentacles, or marginal cirri. There are 16 ocelli, one at the base of 

 each tentacle. These ocelli are situated within the ectoderm of the outer 



