Boyal Physical Society. 447 



rested in the pursuit of natural history, that it is rare for an 

 animal of this magnitude to be brought within the reach of 

 investigation ; and still more so to have an opportunity of 

 adding a specimen, with all the external characters complete, 

 to a national collection. He would therefore suggest, that 

 means should be taken for ultimately securing to the National 

 Museum in the University of Edinburgh the well-preserved 

 specimen of this Bell Rock whale, now in possession of Mr 

 Laird, 22 Constitution Street, Leith. 



III. Observations on British Zoophytes. — (1.) On Atractylis (new genus); 

 (2.) On the fixed Medus ids of Laomedea dichotoma (living speci- 

 mens were exhibited) ; (3.) On the Reproductive Organs of the 

 Medusoid of Laomedea geniculata ; (4.) On the Reproductive Organs 

 of Laomedea lacerata. By T. Strethill Wright, M.D. 



Description of Plates. 

 Plate XXIL 



Atractylis and Eudendrium. 

 Fig. 1. Medusoid of Atractylis ramosa. 



2. Same at third month developed into Bougainvillea Britannica. 



3. Tentacle of peduncle of do. further enlarged. 



4. Atractylis repens. 



5. Medusoid of do. 



Plate XXIII. 



Pig. 1. Male polyp of E. rameum with double sperm sacs — a, b, ectoderm of un- 

 ripe sperm sacs — c, process of endoderm — d, ripe sperm sac with 

 spermatozoa; endoderm absorbed. 

 2. Female polyp of E. rameum — a, ovarian sac containing single ovum 

 surrounded by c, c, process of endoderm. 



On Atractylis (new genus). 



On a former occasion I read to the Society a description of 

 two Hydroid Zoophytes, which I placed in the genus Euden- 

 drium, on account of the similarity which their polyps bore to 

 those of the Eudendrium ramosum of Van Beneden (" Me- 

 moirs of Brussels Academy, vol. xvii., Plate IV."), the Tubu- 

 laria ramosa of Dalyell, although at that time I doubted, with 

 Johnston (" British Zoophytes," vol. i. p. 47), whether Van 

 Beneden's zoophyte did not belong to a distinct genus. Since 



VOL. i. 2 T 



