CORALS AND CORAL-ANTMALS. 



'75 



A more remarkable and (if tenable) far-reaching significance had yet to be associated 

 with this readily-extemporised respiratory organ of the sea-anemone. As first pointed out 

 by the late F. M. Balfour,* the primitive condition of the oral and anal apertures of the 

 generalised type, Peripatus, and several other invertebrata, is that of a continuous, slit-like 

 opening which, by the occlusion of the central area, becomes differentiated into two inde- 

 pendent apertures, the incurrent and excurrent pores, or mouth and vent. The hiatus that 

 previously appeared to separate the coelenterate organism, as represented by an Actinian, from 

 all the higher animals, was thus effectively bridged over; and the Actinia, per se, advanced to 

 a position of closer structural community with the higher Invertebrata. 



So far, only a few of the Madrepores, or Stony-corals, have been proved to possess the 

 important structure denominated by Dr. Hickson the Siphonoglyphe, In the case of the Fungia 



PHOTOGRAPHED FROM A LIVING EXAMPLE OF Fuilgi.l CraSsilentaCuUlta, EXHIBITING THE MOUTH CLOSED, WITH THE 

 EXCEPTION OF THE TUBULAR PASSAGE, SIPHONOGLYPHE, IN THE LEFT VENTRAL GONIDIAL ANGLE. 



investigated by Mr. G. C. Bourne, its presence, while suspected, was not traced, although the 

 animals were observed to close the middle portions of their mouths, leaving small apertures at the 

 extreme ends, through which currents of water passed in and out. While looking through the 

 supplementary photographs taken of Fungia crassitentaculata, the author's attention was directed 

 by his friend. Professor G. B. Howes, to one example, in which the existence of the siphonoglyphe 

 is very clearly recorded. This photograph is herewith reproduced. In addition to illustrating the 



* Cf. .-Xdam Sedgwick "On the Origin ol Metameric Segmentation, and some other Morpliological Questions." 

 Quai-l. Jour. Mia: Sci., XXIV.. 18S4. 



