On Goodsirea mirabilis. 



81 



nucleated cells, joined end to end in a single row, which por- 

 tion terminated in a long ovate head, closely set with the 

 large almond-shaped thread-cells, which were found on the 

 tips of the larger tentacles. All these tubercles and their 

 tentacles were destitute of ocelli. Eight otolitic sacs were 

 attached to the exterior of the circular canal, each containing 

 about four otolites. The sub-umbrella was formed by four 

 lateral canals, with their connecting membrane. Its upper 

 part dipped downward so as to form a funnel, from the end 

 of which the peduncle or alimentary polype was suspended. 

 The peduncle, about an inch and a half in length, was very 

 extensile, and of a greenish white colour. It was terminated 

 by a quadrangular campanulate mouth. The peduncle in the 

 female was rendered quadrangular by the four band-like 

 ovaries, which passed along its whole length, and contained 

 countless eggs. In the male it was cylindrical, and included 

 a mass of spermatozoa between its ectodermal and endodermal 

 layers. The whole of the lateral and circular canals were 

 powdered, as it were, with dark purple pigment granules. 

 When floating in the sea, or jerking itself along by the rapid 

 strokes of its disk, this medusa was only rendered visible by 

 the snake-like motions of its peduncle and tentacles. All the 

 rest of its body was as transparent as glass. In a well-lighted 

 jar of sea-water, the outer surface of the umbrella glowed 

 with tints of blue, purple, and amber, reflected from the thin 

 ectodermal membrane, which covered the gelatinous umbrella. 

 With regard to this gelatinous structure, Dr Wright had 

 come to the conclusion that it was not the homologue of the 

 ectoderm of the polype, but rather a true corallum, homologous 

 with the horny plate of Velella and the corallum of Hydrac- 

 tinia. Did it consist of ectoderm, it would be rendered opaque 

 by alcohol, which was not the case, as might be seen in the 

 specimen on the table. In captivity these animals floated near 

 the bottom of the jar in which they were confined, supporting 

 themselves on their tentacles and peduncle, with which they 

 were constantly searching the bottom, as if for food. One of 

 the females discharged a large number of ova, which were 

 carefully preserved in a proper vivarium, and watched, but no 

 farther development took place in them. Dr Wright had 



VOL. IJ. L 



