1 28 Rev. T. Hincks on the Terms Polyzoa and Bryozoa. 



the date of his paper, but have also thoroughly mastered its 

 contents, and, strange as it may seem to my friend Mr. 

 Waters, have been much confirmed thereby in their opinion. 



As to the question of date there is no room for doubt, and 

 Mr. Waters does not suggest any. The term Bryozoa first 

 made its appearance in the ' Symboke Physical,' in 1831 ; 

 but Thompson's ' Researches,' in which he proposed the 

 name Polyzoa for the type of structure which he had demon- 

 strated in the polypide of the Ascidian zoophytes (for this I 

 take to be what he intended) were published in 1830. And 

 it must be remembered that his observations were made as 

 early as 1820 ; so that he really anticipated not merely Ehren- 

 berg's name, but the discoveries of Grant and Milne-Edwards, 

 though the publication of his results was delayed. Those 

 results are sufficiently remarkable in themselves, and we 

 shall estimate them the more highly when we take into ac- 

 count the conditions under which they were obtained. 



But Mr. Waters makes very light of " the bibliographical 

 question of dates," and is confident that we have but to 

 glance at the paper to convince ourselves that we have been 

 thus far under a delusion. He lays it down that " Thompson 

 did not indicate any group of animals by his term, and that 

 all he meant by Polyzoa was a single polypide ;" and he 

 implies that to make the term a class-designation Avould 

 be to give it a totally different sense from that which he 

 intended. For proof of his position he thinks it unneces- 

 sary to go further than the title of the paper, " On Poly- 

 zoa. a new animal discovered as an inhabitant of some Zoo- 

 phytes." 



This view, it seems to me, rests on a complete misappre- 

 hension of Thompson's meaning. He used the term Polyzoa 

 (in opposition to Hydra) to denote a distinct type of structure, 

 which he had demonstrated, and not as the mere name of the 

 single zooid. This is evident from the following, amongst 

 other passages : — " The Polyzoa will probably be found in 

 many dissimilar genera of the zoophytes, and even mixed up 

 with Hydra in some ; . . . . and hence this discovery must 

 be the cause of extensive alterations and dismemberments in 

 the class with which they have hitherto been associated. . . . 

 I shall merely indicate here in a general way the whole of the 

 Flustracece, in many of which I have clearly ascertained the 

 animals to be Polyzoce ;" which is equivalent to saying that 

 they exhibited the new type of structure, and were thus dis- 

 tinct from the Hydra}. In a word, Polyzoa, as he uses it 

 here, is essentially a class-designation, and not the name of a 

 mere structural element. 



