168 Proceedings of the 



2. Note on Indications of the Existence of Bilateral Symmetry, and 



of a Longitudinal Axis in Actinia, as shoivn in Living Specimens. 



By T. Strethill Wright, M.D. 

 The author stated, that he had lately received from the south of 

 England several specimens of Actinia bellis, which illustrated in a 

 striking manner the existence of bilateral symmetry and of a longitudinal 

 axis, maintained by Agassiz as occurring in this and other classes of the 

 Radiata. The members of the Society would at once perceive that the 

 disks of the animals placed on the table were not circular, but oval ; and 

 that the slit of the mouth intersected the long diameter of the oval. 

 Agassiz had noticed that the faecal discharge in Actinia always took place 

 from one extremity of the mouth, which was indicated by a tentacle of 

 peculiar colour or form. This observation had been confirmed by Dr 

 M'Bain of Leith. In some of the specimens exhibited, the faecal extremity 

 of the mouth was marked by a brilliant yellow tentacle, while all the other 

 tentacles were of the usual mottled-brown colour. Others of these speci- 

 mens, again, exhibited still more remarkable markings. At first sight, 

 their disks appeared to be accurately divided into four quarters, three of 

 which were striped with broad lines of white, whilst the fourth was of 

 an unmixed brown colour. A closer inspection showed that this fourth 

 was intersected by the line of the mouth and the long diameter of the 

 oval, so that in these specimens the bilateral symmetry was perfect, and 

 the existence of an antero-posterior diameter very apparent. 



3. Specimens of living Madrepores (Caryophyllia Smithii), from Ilfra- 

 combe, Devonshire, were exhibited. By T. Strethill Wright, M.D. 



4. A Collection of Scales of the Holoptichius maximus was exhibited ; 

 found on Rule Water, Roxburghshire. By John Alex. Smith, M.D. 



The specimens consisted of single scales, apparently of the Holoptichius 

 maximus, part of a cranial plate, and what appeared to be part of a fin- 

 spine. They were found in the red sandstone rock, on the property 

 of Wolflee, at the head of Rule Water, Roxburghshire, where a small 

 quarry had been opened for building purposes, which Dr Smith visited 

 last summer. He made some remarks on the sandstone formation of the 

 district, and referred to the previous view entertained of its geological 

 position, stating that Mr Alexander Rose had many years ago discovered 

 a scale of the Holoptichius, and satisfied himself as to the formation 

 being really the old red sandstone ; Dr Smith said, from the abundance of 

 scales, although generally in bad preservation, to be found, he believed, 

 all along the river Rule, it was rather astonishing its true position had 

 been so long considered doubtful. 



Committees were appointed for conducting investigations during the 

 summer, and the Society adjourned to November next. 



