69 
JUNE 277TH. 
MICROSCOPICAL MEETING.—MR. T. H. HENNAH ON 
MINUTE CRUSTACEANS. 
He had hoped, he said, to have exhibited good living specimens, 
as they abounded at this time of the year ; but the weather had been 
unfavourable for obtaining the specimens he required. 
One of the most interesting was the Caprella, a living specimen of 
which, under a moderately high power, exhibited the circulation and 
action of the dorsal vessel, or heart, very beautifully. The corpuscles, 
of an oval form, were plainly seen rolling over and over as they per- 
meated the whole body. The intestinal tube extended from 
the head through each segment of the body to the anal 
orifice, situated on the last segment between the articulation of the 
last pair of legs. Surrounding the anal orifice were several tubercles, 
very similar to those round the mouth. 
The habits of the Caprelle led them to keep among the marine 
plants and sponges. They walked like caterpillars, turned frequently 
and rapidly on themselves, or set up their bodies, holding on to the 
alge merely by their posterior legs, vibrating their antenne at the 
same time. Their food was small animalculz, and they had been seen 
greedily devouring cyclops. 
The Caprelle had ten feet ; the first pair were given off from the 
head and then a pair from each segment of the body, leaving out the 
second and third, which had each a pair of vesicular bodies, supposed 
to be respiratory organs. This he certainly believed to be the case. 
From their extreme transparency and the liveliness and peculiarity of 
their action, the caprelle were among the most interesting of micro- 
scopic objects. The rapid course of the blood, the striated muscles ever 
in motion, and the coloured pigment cells were well seen under a very 
“moderate power, while a 3-inch objective took in the whole animal. 
Another minute wonder was one of the Pycnogonids, the Amathea, 
which was found in numbers crawling over the smaller sea-weeds at 
low-water. Without entering into details of the general structure, he 
would proceed to the very interesting arrangement of the digestive 
organs. The orifice of the mouth was prolonged backwards, forming 
an ssophagus, and opened into the stomach at the level of the second 
