Miscellaneous. Bail 
this catalogue is the class of fishes—out of a total of 249 recorded 
British species, only 148 are known to occur in the county and the 
sea that washes its coast. Eighty species of marine fishes which 
occur somewhere in the British seas are unknown on the Yorkshire 
coast ; some of these will probably turn up hereafter; many of them 
are scarce fishes, which have occurred only once or twice anywhere 
round our coasts, or species of southern type which can hardly be 
expected to find their way so far north. 
On the whole, Yorkshire has good reason to be proud of its verte- 
brate fauna; and the authors of this catalogue may with equal 
justice take a pride in their work, which has evidently been exe- 
cuted with most conscientious care. As already stated, it includes 
the whole British vertebrate fauna; and the Yorkshire species are 
indicated by having appended to their names brief statements 
relating to their occurrence in the county, including the localities 
where specimens have been obtained in the case of the rarer species, 
and frequently an indication of the museums in which known 
Yorkshire specimens are preserved. ‘The authors have given a short 
introductory exposition of the principles by which they have been 
guided in the performance of their task, followed by an excellent 
brief sketch of the physical aspects of Yorkshire, and a summary of 
the results of their investigation of its Vertebrata. The little book 
is a most valuable contribution to British zoological literature ; 
and the authors could not have paid a more graceful compliment to 
the British Association in its year of jubilee than by dedicating it, 
as they have done, to Sir John Lubbock, as President of the Asso- 
ciation at the York meeting. 
MISCELLANEOUS. 
On the Origin of the Ovum in the Hydroids. 
By M. A. DE VARENNE. 
Unit lately it was supposed that the ova and spermatozoids of the 
Hydroids are developed in the interior of the gonophores, medusoid 
buds, and Meduse ; and, in fact, these individuals are regarded as 
representing the sexual generations of these animals. Various 
opinions even have been put forward with regard to the endodermic 
or ectodermic origin of the sexual elements in these gonophores. 
M. Goette, however, in a memoir on Hydrella, published in 1880, 
showed that, in that species, the ova attain their complete develop- 
ment in the stem instead of being conveyed into a gonophore ; and 
in the same year M. Weismann observed that, in Plumularia echinu- 
lata, the sexual elements are developed in the stem and afterwards 
pass into the gonophore ; and he has recently demonstrated the same 
fact with regard to the ova in the genus Hudendrium. 
Simultaneously with these two authors, but without any know- 
ledge of their labours, I busied myself with the same question 
last summer at the laboratory at Roscoff; and the following are the 
results to which my observations have led me. 
In Campanularia flexuosa the ova are met with in the endoderm 
Ann. & Mag. N. Hist. Ser. 5. Vol. viii. Ze, 
