QUESTIONS. 357 



158. What is the part generally called the " tail," and what is the so- 

 called " head ? " 



159. What are the " antennae," and how many are there hi the Lobster 

 and in Crustacea generally ? 



160. What are "foot-jaws," and why are they so called? 



161. What are " chelaa ? " 



162. Of what nature are the appendages of the abdomen in the Lobster ? 



163. What is the last segment of the abdomen called ? 



164. Describe the gills of the Lobster. Where are they placed ? 



165. Of what nature is the abdomen of the Hermit-crabs ? 



166. How are the Crabs distinguished from the Lobsters? 



167. By what character does the young Crab approach the Lobster? 



168. Give an example of the Isopoda ? 



169. What is the character of the appendages of the mouth in the King- 

 Crabs ? 



170. What is the structure of a Trilobite ? 



171. What is the nature of the shell of the Ostracode Crustaceans ? 



172. What change do the Cirripedes undergo in passing from the larval 

 to the adult condition ? 



173. What are the two types of the Cirripedes ? Give examples. 



174. Give the general characters of the Arachnida? 



175. What is the structure of the mandibles of the Spiders ? Of the 

 Scorpions ? 



176. To what do the mandibles of the Arachnida correspond? 



177. Of what nature are the breathing-organs of the Arachnida? 



178. What is the structure of tracheae? Of pulmonary sacs ? 



179. What are the organs of vision in the Arachnida ? 



180. What are the habits of the Mites ? Give examples. 



181. By what structure do the Scorpions inflict wounds ? 



182. What is the condition of the abdomen in Scorpions ? In Spiders ? 



183. By means of what organs do the Spiders spin webs? 



184. What are the general characters of the Myriapoda? 



185. What is the general condition of the young Myriapod? 



186. What are the distinctions between the Centipedes and Millipedes? 



187. What is the number of legs in Pauropus? 



188. What are the general characters of Insects? 



189. What organs are carried by the head in Insects ? 



190. How many segments form the thorax, and what appendages do they 

 always carry ? What appendages do they sometimes carry ? 



191. What are " nervures ? " 



192. How many rings generally go to the abdomen of Insects ? What 

 appendages (if any) do these support ? 



193. What are the chief modifications in the organs of the mouth in 

 Insects ? 



194. Describe the digestive system of an Insect? 



195. How is the circulation carried on ? 



196. Of what nature are the breathing-organs ? 



197. Of what nature are the eyes in Insects ? 



198. What is understood by the "metamorphosis " of an Insect ? 



199. What are the chief differences in the metamorphoses of Insects ? 



200. What peculiarity distinguishes the adult state of Insects which 

 undergo no metamorphosis ? 



201. What is understood by the terms "larva," "pupa," and "imago ? " 



202. What is a " chrysalis ? " A " cocoon ? " 



