446 ZOOLOGY. 
borne about until the young hatch. They are probably 
caught up after exclusion and fertilization. Some of these 
eggs are half an inch in diameter. Dr. Day states that the 
same habits occur in certain Indian species of Arius and 
Osteogeniosus. A species of Arius was found by Stein- 
dachner, at Panama, to carry its eggs in a fold of the skin of 
its belly; afterwards the males bear them about in their 
mouth. 
The females of Aspredo have on the ventral surface 
horny, stalked capsules, which contain eggs from one to two 
millimetres in diameter ; the capsules disappear as soon as 
the young hatch. 
Malapterurus electricus Lacépéde, of the Nile, is electri- 
eal, the electric cells forming a layer directly beneath the 
skin and enveloping the whole body, except the head and 
fins. The cells are minute, lozenge-shaped, about one and 
a half millimetres in diameter. They are supplied by a 
nerve from the spinal cord. The shock is comparatively 
feeble, but suffices for defence, “‘ the fish being protected by 
its electrifying coat, as is the hedgehog by its spines.” 
(Owen.) 
Order 4. Scyphophori.—This order, first named and 
characterized by Cope, derives its appéllation from the 
Greek oxdvos, a bowl, and gép, to bear, in allu- 
sion to a peculiarity of the pterygoid bone, which is en- 
larged, funnel-shaped, and excavated by a bowl-like cham- 
ber which expands laterally and is covered by a lid-like bone. 
The brain has a peculiar plicated organ over the cerebellum ; 
the air-bladder is simple, communicating by a duct with the 
intestinal canal. The order comprises two families, the 
members of which inhabit the rivers of Africa; they are the 
Mormyride, represented by a number of genera and species, 
and the Gymnarchide, of which Gymnarchus niloticus is 
the only known species. 
Order 5. Teleocephali.—These are our common types of 
fishes, and are, whether we consider their individual struc- 
ture or the number of specific forms, the most highly de- 
veloped, ¢. ¢., specialized, of the class. The name is derived 
from réAé205, perfect, and xepad7, head, in allusion to the 
