Zoological Society. 299 



having been two hours before less luminous than usual, presented 

 one mass of bright phosphoric light extending to a considerable 

 distance around the vessel. ' The extensive field of bright luminous 

 matter emitted so powerful a light as to illuminate the sails, and to 

 permit a book of small print to be read with facility near the win- 

 dows of the stern cabins. Above this luminous field numerous sea 

 fowl were hovering in search of their prey. The light appeared to 

 be entirely owing to the Pyrosomuta. 



Specimens taken from the sea and placed in a vessel containing 

 sea water, ceased altogether to emit light, or emitted it but spa- 

 ringly while they remained at rest. On the water, however, being 

 agitated, or when one of the masses of animals was taken into the 

 hand, the whole mass became instantly illuminated by myriads of 

 bright dots, much resembling in hue the points on the elytra of a 

 diamond Beetle, Curculio imperialis, Fab. 



The Pyrosoma, thus enveloped throughout its whole extent in a 

 flame of bright phosphorescent light gleaming with its peculiar hue, 

 presented a most splendid spectacle ; the light shed by it was suffi- 

 cient to render objects distinctly visible in every part of an other- 

 wise dark room. If long retained in the hand, or returned to a 

 quiescent state in the water, the luminous spots gradually faded, 

 and no light was visible until the animal was again disturbed, when 

 the illumination instantly returned with all its vivid splendour. 

 After death it emitted no light. 



The mass of Pyrosoma, of the usual cylindrical form and gelati- 

 nous substance, was about 4 inches in length and 1£ in circum- 

 ference. The tube, passing along its middle, is described as being 

 open at both ends ; the orifice at the broader extremity being much 

 better defined in its circular form, larger, and more distinct than 

 that of the opposite end. The surface of the mass appeared to be 

 studded with numerous prominent rigid and pearly tubercles inter- 

 mingled with small specks of a brown or red colour. In these latter 

 the power of emitting light appeared chiefly to be seated, these 

 being frequently bright while the remainder of the body exhibited 

 only its natural white or yellowish white hue ; a hue which changed 

 after death into a red tinge. The brown specks, when removed from 

 the body, did not emit light. 



A " Description, with Additional Particulars, of the A pteryx Au- 

 stralis of Shaw," by Mr. Yarrell, was read. It described in greater 

 detail than the communication made by the author on February 12, 

 the external structure of this singular bird. It also observed 

 on its probable habits, and on its place in the natural series in 

 immediate relation with the Struthionidte. Following up the history 

 of our acquaintance with it, which commenced with the possession 

 by Dr. Shaw of a single perfect skin (hitherto unique and brought 

 under the observation of the Society by the kindness of the Presi- 

 dent, of whose collection it now forms part), Mr. Yarrell referred 

 to the incidental notices of it by Captain Cruise, M. Lesson, M. Du- 

 perrey, and M. Gaimard, and from the evidence thus collected 

 pointed out its locality to be Mount lkou-Rangui, near East Cape, 



2Q2 



