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VII. Notes on the Genus Hydaticus (Leach), with De- 
scriptions of new Species. By the Rev. Hamuer 
Ciark, M.A., F.L.S., V.-P. Ent. Soc. 
[Read Ist August, 1864. ] 
Durine Dr. Schaum’s late visit to England, he was good enough 
to propose to me that we should combine together to prepare 
a complete and accurate Catalogue of all the known species of 
Hydrocantharide, with the object of offering our manuscript to 
the trustees of the British Museum as a second edition of their 
Catalogue of this interesting group (the first edition, prepared in 
1847 by Dr. Schaum and Mr. Adam White, having long since been 
exhausted): very willingly I accepted his suggestion, and hence 
have occupied myself in examining the exotic species of the 
different genera, being not without hope that the Museum autho- 
rities would receive such a contribution, especially as Dr. Schaum 
has, with infinite labour, succeeded in mastering the most difficult 
portion of the work, the elucidation and determination of the /uro- 
pean species, for his forthcoming volume of Erichson’s Naturgesch. 
d. Ins. Deutsch]. The following notes are the result of my exa- 
mination of the species of //ydaticus, a genus which, in ccloration 
of the forms composing it, is the most beautiful of all. I ought 
to add, that Dr. Gray, some months ago, most liberally placed at 
my disposal for examination the undescribed species of the genus 
in the Museum Collection. At that time, however, I was unable 
to enter upon the subject, and therefore returned the specimens. 
The following paper, being prepared in the country, does not con- 
tain descriptions of those new species referred to in the British 
Museum Catalogue under manuscript names, 
It is worthy of remark, that the most important additions that 
have been made during the last few years to my collection of this 
group have been made by non-entomological friends residing 
abroad, who have kindly interested themselves in sending home, 
from time to time, the results of their examination of their re- 
spective neighbourhoods. Englishmen, like water-beetles, are 
found in every region of the globe. There are few Entomologists 
who have not one or more friends living for a time in some foreign 
