
Toe NorTHERN Muicroscoprst. 


No. 16. APRIL. 1882. 

THE CYPRIS: AND ITS FOSSIL ANCESTORS. 
By Re TT? BURNE TES EeGis; 
’ A Paper read before the Manchester Microscopical Society. 
HE Cypris is a small bivalve, of the class Crustacea, sub-class 
Entomostraca, and of the tribe Ostracoda. He is a very active 
little fellow and is almost a perfect cosmopolitan, being found, as 
we shall hereafter see, under the general term Ostracoda, in all 
parts of the globe, living in sea water, brackish water, and clear 
water. Very few seas are without him. He flourishes abundantly 
in estuaries, is to be found in running waters, and loves ponds, 
both sweet and foul. The foregoing applies to the tribe more 
particularly to which our Cypris belongs than to the small crusta- 
cean itself. | ; 
The “pond hunter,” upon turning out the contents of his bottle 
after reaching home from a collecting expedition, will invariably 
come upon an oblong object about one-tenth of an inch in length, 
somewhat resembling a kidney bean in shape, and of a dark green 
colour with markings of paler green. Upon watching the object 
for a while he will observe it suddenly rise up swiftly from the 
bottom of the jar in which he may have placed his “ finds,” and 
appear to paddle itself along with great rapidity, suddenly to 
change its course, and as rapidly descend once more to the bot- 
tom, and seek refuge in whatever muddy deposits it can find. 
Upon attentively watching it again, he will see that it propels itself 
with leg-like organs, which appear to project a slight distance only 
beyond the main bulk of the object from its fore part and under- 
sides. This kidney-shaped object is our little Cypris. 
Take him out and for a moment lay him upon a piece of paper, 
and examine him through your pocket lens, when behold you find 
the “legs” have almost disappeared, and you see but a minute, 
bean-shaped shining little object, with a fine line running from*end 
to end, where before you had seen the “legs.” Turn him over 
and you see that that which you took for a line-marking simply is 
in fact the line of opening identical to those of the oyster, mussel, 
or cockle; it is in fact the lips of two valves which are united 
on the opposite sides with a hinge in like manner to the mussel, 
VoOm22: 
