QUESTIONS. 57 



92. In what respects do fishes resemble, and how do they differ 



from the Amphibia ? 



93. What is the nature of the skeleton in fishes ? 



94. What is meant by "amphiccelus" ? 



95. What is the nature of the limbs in fishes ? 



96. What are "fins"? 



97. How are the "median" fins distinguished from "paired" 



fins? 



98. What pairs of fins correspond respectively to the legs and 



arms of a man ? 



99. By what names are the median fins which surround the body 



known? 



100. What are " interspinous bones" ? 



101. What is the distinction between a "heterocercal" and a 



" homocercal" tail ? 



102. How does the tail of a fish differ from that of a whale ? 



103. Describe the digestive apparatus in fishes. 



104. What are " pyloric caeca" ? 



105. Describe the heart, and the course of the circulation in 



fishes. 



106. What is the " bulbus arteriosus" ? 



107. Describe the process of respiration in fishes. 



108. How do gills differ from lungs ? 



109. What is the " operculum " of a fish ? 



110. What is the nature and use of the " swim bladder " ? 



111. Describe the brain of a fish. 



112. How do the nostrils differ from those of other vertebrates ? 



113. Describe the organs of hearing in this class. 



114. What is the nature of the covering of fishes ? 



115. What are the different forms of fish scales ? 



116. What is the " roe," and what is the " milt" ? 



117. How does the lancelet differ from ordinary fishes ? 



118. What are the peculiar features of the lepidosiren ormud-fish? 



