54)4 Mr. W. S. Macleay's Anatomical Observations 



fact from all other species of Tethya, not only with respect to the 

 singular form of the intestinal canal, but inasmuch as the branchial 

 vein is thus placed, in relation to the pharynx, directly opposite 

 to its position in all other animals of this group. I therefore am 

 induced in some measure to suppose that there is a monstrous 

 formation in the intestinal canal of the only specimen which I 

 have had the means of examining ; a supposition which must of 

 course for the present throw doubt on any generic character 

 which might be drawn from the above description of the intes- 

 tinal canal. If, indeed, we could imagine that, were it not for 

 some monstrosity of structure, the intestinal canal would com- 

 municate with the branchial cavity by that end which, from its 

 being free, I have been obliged to consider the anus, then the 

 whole of the internal organs of nutrition would have a situation 

 analogous to that of those of Boltenia. For instance, there would 

 then be a short oesophagus opening near the anal orifice of the 

 envelope, an ascending stomach, a long curved intestine, and 

 descending rectum, while the branchial vein and heart would 

 take their usual situation in respect to the pharynx and stomach. 

 We know, moreover, from those Memoirs of Savigny, to which 

 I have in the course of this paper had so often occasion to refer, 

 that the digestive organs of the Tunicata are subject to analogous 

 derangements, of which he has figured two remarkable examples 

 in Cynthia momus and Phallusia turcica. It appears, indeed, to 

 be a consequence of the low rank of these animals in the scale 

 of being, and of their simple organization, that the organs appa- 

 rently most essential to their existence may undergo the greatest 

 inversions without affecting their life ; for the monstrous Cynthia 

 momus, described by Savigny, as well as the Cystingia, now under 

 consideration, had its ovaries full of eggs. 



The Cystingia Griffithsii has no liver very distinct, unless a 

 substance which appears to coat a very small part of the sto- 

 mach 



