20 DTTBLIX XATURAL HISTORY SOCIKTY. 



birds, such as the jay cuckoo, cow-cow bird, belted kingfisher, Egyptian 

 goose, soft-billed duck, &c., have mostly occurred in the winter. I muyt 

 apologise for the length to which these remarks have run ; but that they 

 were called for is sufficiently shown by the constant remarks of wonder- 

 ment met with in authors, as to the absence in Irish and Scottish lists 

 of species met in England, and also occurring much further north, I 

 hope to return to the subject at some future time, and will now conclude 

 by calling attention to the fact that, by examination of the few dates 

 given, it will be seen that these accidental occurrences of species have 

 occurred neaiiy in the same years, showing that the same causes have 

 caused divergence from their usual routes in almost every case. 



Mr. Kobert J. Montgomery confirmed Professor Kinahan's paper, as 

 far as the frequency of the occurrence of summer migrants in winter was 

 concerned. He submitted a list of species obtained by him in this 



The Rev. Eugene O'Meaba read the following : — 



NOTES ON THE EEPRODUCTION OF DIATOMACE^. 



At a meeting of this Society, held on May 7, 1858,* Dr. Harvey, the 

 President, in the Chair, I communicated the fact of having observed 

 bodies, which were considered to be zoospores, issuing from a frustule 

 of Pleurosiynia 82')cncerii. The President considered '' the observation 

 perfectly new, and had no doubt, as such, would be controverted, or at 

 least probably received with doubt. There was, therefore, he thought, 

 the more necessity for repeating the observation, and, if possible, con- 

 firming it." Since that time my attention has been dii'ected to the sub- 

 ject, and, in consequence, I have the gratification of bringing under the 

 notice of this meeting a fact corroborative of the former observation. In 

 October last I brought home a fragment of Myriophyllum I had ob- 

 served floating on the canal near Lucan. Upon examination of the 

 gathering, I found it to contain some species of Diatomacese, those which 

 occurred in greatest abundance being Epitliemia argus, Epitliemia gilha, 

 and Coeconeis loediculus. In many instances the frustules exhibited 

 precisely the same abnormal appearances as had been previously ob- 

 served in the case of Pleurosigma &iocncerii, the endochrome, instead of 

 the usual brown colour, being bright green-, and the frustules in the 

 present case, as in the former, filled with vesicles similar in appearance 

 to oil-globules. 



Among the numerous forms presented to view, a specimen of Efi- 

 themia gihha speciall)^ arrested my attention, in consequence of the pecu- 

 liarly vivid greenness of the endochrome, as well as an unusual move- 

 ment of the vesicles within the ccU. In the space of a few minutes I 

 saw several of these vesicles extended from the frustule, and with a very 



Vide " Proceedings," vol. ii., p. 108. 



