8o Invertebrate Zoology, 



In front of the first maxillae are the strong jaws or man- 

 dibles, each provided with a jointed accessory portion, the 

 palpus. 



Two pair of antenna lie somewhat in front of the jaws. 

 The first antenna are shorter and biramous ; the second, 

 longer and with only a single filament. 



The compound eyes are borne on stalks which are, by 

 some, considered to represent appendages. Beginning with 

 the eye-stalks, enumerate the segments of the entire animal. 



Find the following openings : (a} The openings of the 

 auditory organ, each situated at the base of the first antennae 

 and opening from the upper surface. () Of the excretory 

 organs or green glands, on the lower side of the second an- 

 tennae. (V) The mouth, between the mandibles, (d) The 

 oviducts, in females at the base of the third pair of ambula- 

 tory appendages, (e) The openings into the receptive ap- 

 paratus, if the specimen is a female, in the angles of the 

 heart-shaped structure between the next succeeding pair of 

 appendages. (/") The seminal openings of the male, at the 

 bases of the last pair of thoracic appendages, (g) The anal 

 opening in the last segment (telson) of the abdomen. 



Is there anything to show that some of the paired open- 

 ings may be homologous ? 



Comparative Study of the Appendages. Examine 

 one of the appendages of the fourth abdominal segment. It 

 will be found to consist of an elongated basal portion, the 

 protopodite, bearing two blades, the cndopodite within, and 

 the exopodite without. Remove the left appendage where it 

 joins the body and draw it as seen from in front, naming the 

 parts. Compare with the appendages of the second, third, 

 and fifth abdominal segments. Compare now with the first 



