The Scottish Nattiralist. 
m 
any British species, I submitted specimens to Prof. G. S. Brady, 
F.R.S., who recognised it as the Diaptomus serricornis of Lilljeborg. 
Professor Brady informs me that hitherto it appears to have been 
observed only in Lapland, and is thus an interesting addition to 
the British Fauna. Both male and female specimens occurred in 
the material. The male is readily distinguished by possessing a 
toothed appendage at the distal end of the third last segment of 
the right anterior antenna. 
Canthocamptus northumbricus, Brady. My son, Mr. 
A. Scott, obtained this species some time ago in Duddingston 
Loch, Edinburgh. It is quite distinct from any other British 
Canthocamptus, and is easily recognised. Each abdominal seg- 
ment has two rows of stout setae round the posterior margin. 
There are other striking, though less obvious, characters by which 
the species is distinguished. Attheyella spinosa, Brady, is also 
frequent in Duddingston Loch. This, and the Canthocamptus, 
are described and figured in the Monograph of the British Cope- 
poda by Prof. Brady. 
Monstrilla, Dana. This curious genus of the Copepoda is 
now represented in the Forth Fauna by at least two species, viz., 
Monstrilla rigida, I. C. Thompson, and Monstrilla helgolandica, 
Claus. The first was obtained off Musselburgh, and the other 
near the Bass Rock, and also west of Queensferry. Monstrilla 
differs a good deal from the Corycoeidoe, among which the genus 
is provisionally placed. The mouth organs are almost altogether 
absolete in Monstrilla, and only one pair of antennae are developed. 
There is also present in both male and female a peculiar genital 
appendage, not observed in any other genus of the family. Mon- 
strilla thus differs very markedly from all the other Coryco&idcB, 
Monstrilla was first added to the British Fauna by Sir John 
Lubbock in 1857, but for the next thirty years no specimens of 
Monstrilla were recorded from our seas. In 1887, I. C. Thompson, 
F.L.S., obtained near Pufhn Island, Anglesea, the species de- 
scribed by Sir John Lubbock in 1857. Since 1887, Monstrilla 
has been recorded from various places, and there are now seven 
species described as belonging to the British Fauna. Several 
specimens have been taken in the Forth, but usually not more 
than one or perhaps two at a time. I have also taken Monstrilla 
