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G. W. SHRUBSOLE FURTHER jSTOTES OX 



before the Glasgow Natural-History Society, mentions the occurrence 

 of the same in Fenestella tenuifila, Phill. Thus we have the record 

 of this peculiar cell- aperture in two if not three species of Fenestella. 

 Notwithstanding this evidence in favour of the denticulate aperture 

 in Fenestella, I now hesitate to give this feature wholly or in part 

 to it, since I made the discovery that some of the species of 

 Glauconome possessed a fenestration not very dissimilar to that of 

 Fenestella, and might easily, in a fragmentary condition, be mistaken 

 for it, indeed have been so. There is no doubt about the fact that 

 some of the species of Glauconome have the denticulate cell-mouth 

 in question — Glauconome stellipora, Young, for instance ; on the 

 other hand, it is not equally well established that the cell-mouth of 

 Fenestella had the same characters. There is the possibility that 

 some of the fragments of reputed Fenestella upon which the 

 denticulate aperture was seen, may prove to have belonged to 

 Glauconome. This discovery of the fenestrate polyzoary in Glau- 

 conome considerably complicates the question of the nature and 

 relationship of the palaeozoic Polyzoa ; and it will require careful ob- 

 servation on the part of palaeontologists to work out the distinctive 

 characters of the several genera, and assign to the various species 

 the right fenestration. The result will have an important bearing 

 upon Glauconome, more than on Fenestella, since we know so little 

 of the life-form of the former, whereas the latter is better under- 

 stood. It may be that both Glauconome and Fenestella and kindred 

 Polyzoa, possessed the denticulate aperture. It is so far certain, 

 as regards Glauconome ; it may ultimately prove to be true of 

 Fenestella. But for the present I consider that Glauconome has 

 absorbed the existing evidence of the peculiar cell- aperture in favour 

 of its claims. The other problems remain to be worked out. 



I will now allude to a connexion which has become apparent 

 during this inquiry between Fenestella nodulosa, Phill., and Palceo- 

 coryne, a hydrozoan originally described by Prof. Martin Duncan 

 and Mr. Jenkins from the Lower Limestone shales of Ayrshire. 

 With regard to my facilities for observing Palceocoryne, I may 

 remark that it was described * from specimens washed from the 

 shale, a process necessarily destructive of many of its more 

 delicate and distinctive features. All the specimens in my posses- 

 sion, on the contrary, are in situ on the shale or limestone in which 

 they were found. Prof. Duncan, speaking of it, says that " usually 

 they are attached by a dactylose pseudo-cellular base to the margins 

 of the polyzoaria of Fenestella} "f. My observations would lead me 

 to limit the attachment of Palceocoryne to one species of Fenestella, 

 viz. Fenestella nodulosa, and to the pore-face generally, rather than 

 the margin of the polyzoarium. The frequency with which I 

 noticed this association of Palceocoryne with Fenestella nodulosa, 

 led me to go carefully over my collection, and ascertain definitely 

 the particular species of Fenestella with which it was most fre- 

 quently allied. The result was, that, out of ninety-seven specimens 



* Explan. Sh. 23, Geol. Surv. Scotland, p. 96. 

 t Quart. Journ. Geol. Soc. vol. xxix. p. 413. 



