CRUSTACEANS 
straight, the surface smooth, variously banded with pale yellow and 
green.’ In Candona candida the lower margin is sinuated, especially in 
old examples and adult males, and the surface of the shell is smooth, 
pearly or yellowish white, with darker yellow cloudings towards the 
dorsal margin.” 
Of the Copepoda, Dr. Brady in his Revision of the British Species of 
Freshwater Cyclopide and Calanida attributes to Bedfordshire two species, 
both from Pavenham and both on Mr. Scourfield’s authority. They 
are both extensively distributed species, Cyclops bicuspidatus, Claus., and 
Diaptomus castor (Jurine), the former assigned by Brady to the family 
Cyclopidz, the latter to the Calanidz.? The genus Diaptomus, Westwood, 
should rather be included in a family Diaptomide, of which it is the 
earliest and apparently the most extensive genus, comprising three or 
four scores of species. The range of D. castor is stated to be the whole 
of Europe, its occurrence in North America also having been reported, 
but not thoroughly ascertained. The length of a specimen varies from 
a twelfth of an inch to an eighth or even a seventh. Cyclops bicuspidatus 
is smaller still, as it reaches its upper limit in a twelfth of an inch, 
while starting from a nineteenth. In Diaptomus the first antenne are 
twenty-five jointed ; in Cyc/ops the number of joints in these appendages 
varies from six to eighteen, reaching seventeen in C. dicuspidatus. 
According to Mr. A. R. Thompson’s paper above quoted many 
species of fish frequent the waters of the river Ouse. The supposition 
therefore is well warranted that in the same waters parasitic Copepoda 
frequent those fishes. It is indeed quite certain that the hitherto unre- 
corded crustaceans of Bedfordshire would fill a far longer catalogue than 
can be composed of those which have as yet been publicly noticed. 
1 Trans. R. Dublin Soc. ser. 2, iv. 85. 
2 Brady, Trans. Linn. Soc. (London, 1870), xxvi. 383. 
3 Nat. Hist. Trans. Northumberland, Durham and Newcastle-upon-Tyne (1891), vol. xi. pt. 1, pp. 
799 94- 
