NEW GENUS OE AMPIilPOD CRUSTACEANS. 
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pairs of abdominal feet, consisting of a quadrate basal joint, to which are attached two 
feathered appendages. These are followed by two segments, to each of which are 
attached a pair of appendages, the four forming together the tail. Each of these 
appendages is bifurcate with a sharp and a rounded point. The rounded termination is 
milk-white, and is separated from the main piece of the appendage by an articulation. 
The anus is situated at the end of the last segment. 
The Muscular System. — The animal is so transparent that all the main muscles are 
clearly visible ; but they do not seem to present any thing very remarkable, with the 
exception of those of the thoracic legs, which are only very weakly developed. From 
this I suppose that the movements of the animal are not very rapid -when it is obliged 
to walk over the sea-bottom. It may be, however, that, like Phronima, it makes but 
little use of these legs, and swims by aid of the abdominal feet only ; these also are 
very small in relation to the size of the body. 
The Nervous System. — The transparency of the body makes it possible likewise to 
distinguish clearly the cephalic ganglion and the ventral chain, consisting of five thoracic 
and three abdominal ganglia (Plate XLIX. fig. 1). The cephalic ganglion is situated in 
the anterior part of the head, more on the dorsal than on the ventral side; it is 3 - 50 
millims. in width, and is horseshoe-shaped with pointed ends. From the middle of its 
anterior margin two large nerves run straight to the end of the antennae, while from the 
opposite side two commissural cords run backwards, traversing the head and, after having 
encircled the mouth, uniting with the first thoracic ganglion. The nerves passing from 
the sides of the cephalic ganglion are all employed as ocular nerves to supply the huge 
compound eyes. Those of the anterior end are better seen, as they go to the anterior 
part of the eyes, while those of the posterior end seem to go to the posterior parts. 
The first thoracic ganglion is seated just underneath the ovary in the second segment, 
and sends out the nerves for the mouth and for the genital organs. The two cords then 
separate till they are united again in the third segment in the second ganglion ; thence 
they run backwards in a single chain and form a ganglion in each of the subsequent 
segments, sending nerves to the legs. Altogether we find five thoracic ganglia for six 
segments, and in the abdomen three ganglia for five segments. The last ganglion of 
the abdomen is more slender than the preceding ones, and seems to send out nerves in 
different directions, especially to the anus and caudal appendages. In Phronima there are 
ten pairs of ganglia, five of which, as in the present case, are thoracic and five abdominal. 
The Eyes are contiguous, the line separating them being, however, clearly visible : 
the length of this line is 20 millims. The eyes thus occupy a rectangular space, the 
outer edges of which are separated from the spiny borders of the head-shield by a 
space 6 millims. in width. At the front of the head there is a space of 3 millims. 
betwmen their anterior borders and the line into which the two antennae are inserted. 
Along the sides of the eyes there is a brownish line produced by elongated chitinous 
appendages, 0T40 millim. long (Plate L. fig. 8), attached irregularly to the borders 
of the cornea. These appendages are hollow tubes pointed and closed at the top, and 
