DAPHNJADiE. 
73 
extremity of the beak, — an opinion adopted also by 
Ledermuller. Schceffer was the first who showed its 
true situation, and De Geer confirmed his observations. 
Schoeffer describes also the two mandibles, and fancied he 
likewise saw the lips, but could not make them out dis- 
tinctly, from the smallness of the animal. 
The digestive canal (t.VIII, f. b) commences immediately 
behind the mouth, in the form of an oesophagus, which is 
short, narrow, slightly curved, and stretches obliquely 
forwards and upwards, terminating immediately behind 
the brain, in the stomach. 
The stomach (f. b, e) is in form of a large vessel, curved 
at its upper part into a complete arch, nearly straight in 
its course downwards through the body, and suddenly 
bending up again in the abdomen. It runs almost all 
the length of the animal, opening by the anus between 
the first two dentated arches of the posterior part of the 
last segment of the body. Immediately behind the eye, 
near the cardiac extremity of the stomach, we see two 
vessels (f. b, d ) 9 curved upwards, in the form of a letter S 
reversed, the arch turned towards the eye; these are 
described by Schceffer, who considers them as organs for 
furnishing the necessary juices for the nourishment of the 
body. De Geer says they resemble crnca. Jurine sup- 
poses them to be organs proper for furnishing a juice 
destined to perfect digestion. Straus at first considered 
them as such also ; but, upon more mature examination, 
at length concluded them to be really caeca. 
The body of the animal is quite free, and unattached 
within the valves of the shell. It is slender and long, and 
is divided, according to Straus, into eight segments ; the 
first of which is the largest, and is the only one which is 
attached to the valves. At the second segment the body 
suddenly diminishes in vertical diameter, sinking down, 
and leaving above a strong projection, formed by the first 
segment. From this projection, throughout the rest of 
its extent, the body is unattached to the shell, and leaves 
a vacant space between it and the edge of the valves, into 
