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PKOFESSORS T. W. BRIDGE AND A. C. HADDON 
Fig. 57. Ventral view of the two air-sacs, showing their relations to the 
osseous capsules ; X 2. 
Fig. 58. The right tripus ; X 2. 
Figs. 59-63. — Auchenipterus nodosus. 
Fig. 59. Ventral view of the anterior vertebrae and the “ elastic-spring” 
apparatus. 
Fig. 60. Similar view of the interior of the air-bladder. 
Fig. 61. Lateral view of the air-bladder and skull, showing the left protractor 
muscle of the mechanism. 
Fig. 62. Ventral view of the right tripus. 
Fig. 63. Dorsal view. 
Figs. 64-66. Oxydoras hrevis. 
Fig. 64. Ventral view of the anterior vertebrae and the “ elastic-spring” 
mechanism ; X 2. 
Fig. 65. The left tripus ; ventral view ; X 2. 
Fig. 66. Ventral view of the interior of the air-bladder ; X 1^-. 
Fig. 67. — Synodontis schcd. Ventral view of the anterior vertebrae and the “ elastic- 
spring” apparatus. 
Figs. 68-70. — Ccdlomystax gagata. 
Fig. 68. Side view of the anterior vertebrm, showing the left osseous capsule 
and its air-sac, the lateral cutaneous area of that side having 
been removed ; X 2. 
Fig. 69. Lateral view of the anterior portion of the trunk. 
PLATE XVII. 
Fig. 70. Ventral vieAV of the osseous capsules and their contained ah’-sacs ; 
X 2. 
Figs. 71, 72. — Malapterurus dectricus. 
Fig. 71. Interior of the air-bladder; ventral view. 
Fig. 72. Side view of the hinder part of the skull and the anterior vertebrae, 
showing the left elastic-sjiring and its protractor muscle. 
Figs. 73-77. Aspredo cotylophorus. 
Fig. 73. Base of the skull and the anterior vertebrae ; ventral view. 
Fig. 74. Vertical longitudinal section of the liinder part of the skull and 
the anterior vertebne ; X 2. 
Fig. 75. Lateral view of the hinder part of the skull, the pectoral girdle, 
and the first, the complex, and the fifth vertebrae ; X 2. 
Fig. 76. Ventral view of the two air sacs in dtu. 
Fig. 77. Ventral view of the interior of the two air-sacs. 
