MUSEUM OF COMPARATIVE ZOOLOGY. 143 



Sars gives a good account of the process of germination in L. octopunctata. 

 This descri2)tion applies also to L. grata, but he was not able to trace the 

 medusa up to what I believe is its adult. The oldest Lizzia which Forbes 

 figures is also immature. My account of the sequence in the development 

 of the tentacles is different from that which Mr Agassiz gives (Proc. Bost. 

 Soc, 1862). 



L. grata was found in abundance at Newport during all the summer months. 

 Its small size and transparent bell would render it inconspicuous, if not in- 

 visible, were it not for the eight black pigmented ocelli on the bell margin at 

 the bases of the tentacles. Four of these ocelli are situated near the point 

 where the radial tubes join the margin of the bell, and four on the beU rim 

 midway between the radial vessels. 



The bell is deep, campanulate, and in older specimens has a pointed apex. 

 The surface is smooth in the adult, and destitute of papillae. The relative size 

 of all the organs can be seen by a study of Plate I. fig. 1. The line at the left 

 of the figure indicates its size. The proboscis is never, except when the bell is 

 abnormally reversed, extended outside of the bell opening, but it generally 

 reaches down about half of the whole height of the bell cavity. The stomach 

 is mounted upon a peduncle, which resembles the substance of the bell walls 

 in its transparency. The chymiferous tubes are small, simple, and without 

 lateral glands or appendages. They are four in number, and, extending along 

 the sides of the pedunculated proboscis, open into the stomach. Near this ter- 

 mination the peduncle bears a cluster of peculiar cells. 



The stomach is four-sided, w4th oral tentacles which impart to it a cruciform 

 shape when seen from below. The extremity of each oral tentacle is bifid, and 

 the end of each bifurcation is thickly covered with many small cells or peduncu- 

 lated knobs. Near the bifurcation of the oral tentacles from the axis of the 

 proboscis are also similar clusters of knob-like organs of smaller size than those 

 mentioned. The tentacles are short, very flexible, hollow, uniform in size, and 

 with smooth surfaces. They are arranged in eight clusters, which in most 

 stages of growth have an inequality in the number of component tentacles. 

 The junction of each cluster with the bell margin forms a triangular bulb or 

 ocellus, which in the adult is dark brown and black. 



There are no otocysts on the bell margin. Claparede was unable to find the 

 male of the Lizzia which he studied. Forbes mentions the male Lizzia a.s 

 larger than a female, with the attached buds. Mr. Agassiz figures a male 

 of L. grata, and calls the sexual structure near the base of the proboscis " sex- 

 ual sacs." I have observed large Lizzia which were females, in which the 

 power of germination seemed to have ceased, or to have become dormant, 

 although from the proboscis of the same medusa young had previously formed 

 by budding. A Lizzia in this condition may have been called a male by 

 Forbes and Agassiz. The essential elements of the male were not detected in 

 L. grata. It would be a very interesting fact to determine whether Lizzia lives 

 for any length of time after the process of germination from the proboscis has 

 ceased, and, if such is the case, whether true ova and spermatozoa are then de- 



