HARDWICK&S SCIENCE-GOSSIP. 



227 



-with the individual polyzoon to which it is attached, 

 whilst the base of Palaeocoryne covers a large number 

 •of the individual cells of Fenestella."* 



With all due respect for the observations of Mr. 

 Jenkins on the appendages of Bicdlaria tuba, I must 

 differ from him entirely as to the value of his evi- 

 dence. Through the kindness of Miss Gatty I have 

 carefully examined the polyzoaries of this and other 

 species, and also several of the hydrozoa in her 

 splendid collection, and after the most careful 

 scrutiny — and Mr. Hincks by his silence on this 

 point seems to confirm my view — I cannot find any- 

 thing having the least similarity to Palaeocoryne. 

 " The fossil appendages in no way resemble those of 

 recent polyzoa or hydrozoa, either in structure, 

 function, or use." t 



With regard to Paloeocoryne being parasitic on 

 Fenestella, the statement of Mr. Jenkins seems to me 

 to be equally unscientific. I have during the last 

 two years examined hundreds of these so-called 

 organisms, and in no case have I ever witnessed a 

 single specimen, isolated or in situ, that would in 

 any way substantiate the morphological view of 

 either Dr. Duncan or Mr. Jenkins as to the parasitic 

 character of Palseocoryne. In some of the best 

 specimens of Mr. Young, in some of my own speci- 

 mens, in those that I have examined of the late Mr. 

 Harker of Richmond, and in many of the specimens 

 of Mr. Shrubsole, these processes spring at right- 

 angles from the celluliferous face of the polyzoon ; 

 they in no way interfere nor interrupt the cell arrange- 

 ment of the fenestrules in any other sense than that 

 which I shall give farther on. The cells are continued 

 along the base of the process on both sides, as shown in 

 the diagram sketch of Palseocoryne, Fig. 47 (Science- 

 Gossip, March 1879). Sometimes these processes 

 are crushed down upon, and they may by this means 

 conceal, the cells, when apparently the P. radiata of 

 Duncan seems to be seated upon the Fenestella ; 

 and I do not fear to hazard the statement that in 

 no case is there a separate identity in Palaeocoryne, 

 and in no case have I found a specimen that would 

 indicate a parasitic attachment similar to the attach- 

 ment of Diastopora megastoma (M'Coy), one of the 

 commonest of the parasites found upon Fenestella. 

 Furthermore, every correspondent who has sent me 

 specimens of Palaeocoryne from his own locality, 

 has prefaced his remarks upon the species with a 

 doubt respecting the hydroid character of the 

 organisms. 



Such is the historical sketch of Palaeocoryne. All 

 the papers referred to are easily accessible to the 

 student, and are well worth the attention of the 

 general reader, who may be interested in Paljeonto- 

 logical questions. 



It must be assumed that the whole polyzoary of the 

 Fenestella originated from some fixed spot on which 



* Ibid. vol. xxx. 



f Rev. Thonas Hincks' corrections of my own reading. 



an embryo had rested. The first process in the 

 development would be a prolongation of the attach- 

 ment, but what this prolongation was I am unable 

 to say. If I call it a root, any reference to ordinary 

 roots would be fallacious — for of primary roots I 

 know but little. Nearly all that pass by that name 

 are processes developed from the matured, or partially- 

 matured frond. A primary root there must be, but 

 this can only be studied in well-preserved specimens 

 of F. frutesc. In a figure of F. membranacea before 

 me the "rootlets" are processes springing from the 

 lower and lateral portion of the conical expansion, 

 some of which bifurcate in a most peculiar way, but 

 at the part of the frond where we should naturally 

 look for the primary root it is absent. There is, 

 however, a great difference in the development of 

 Fenestella from the root over that of the processes. 

 Just above the true root, the formation of the 

 fenestrules are very lax, so much so, that Phillips 

 was often deceived by this laxness of fenestrule in his 

 diagnosis of species. In the more general develop- 

 ment of the polyzoary of even the same species, there 

 is an almost perfect uniformity of fenestrule. Several 

 of my specimens show this laxness and uniformity of 

 fenestrule in a most beautiful manner, but many 

 of Mr. Shrubsole's specimens that have passed 

 through my hands show it more perfectly than any 

 that I possess, and these remarks are founded upon 

 the study of his rather than my own. 



The polyzoary once established, the development 

 of the colony would be carried on by ordinary pro- 

 cesses, or by budding. 



From a section of a beautiful fragment of F. plcbcia 

 in my possession I have been able to give an exact 

 outline of several of the cells * and fenestrules of this 

 species. (Fig. 202, Science-Gossip, p. 248, 1878.) 

 On this particular part of the polyzoary a colony of 

 Diastopora megastoma had taken up their home, and 

 the cells were well preserved in consequence. In 

 this specimen, the cells (or zocecia) and fenestrules 

 are of a regular and definite shape. On the borders 

 of some of the fenestrules of this specimen, but not 

 in the figured part, there are five pores on one side, 

 and four on the other. The cells are opposite on 

 the borders, and alternate on the whole length of the 

 branch. Here development is by budding, and the 

 dissepiments are originated by the lateral expansion 

 of the zooecium (a), Fig. 202. In fact, the dis- 

 sepiment is nothing more than a portion of the 

 zooecium budding to originate another cell in an 

 opposite direction. I want the reader to note this 

 fact — one that I give the more prominence to now 

 since Professor Allman has stated his views to the 

 Linnean Society, on the perfect zooidal individuality 

 of both the cell and the polypide : " This compound 

 animal is composed of two zooidal individuals : 



* Since this was written, I have been able to confirm my 

 originally-formed views by sections of Fenestella, wonderfully 

 preserved in the form of casts in sandstone, from the sandstones 

 of Kirkcaldy, kindly furnished by Mr. Shrubsole. 



