A^M "MY OF THE LOBSTER, 8l 



thirteen pairs of cepbalo thoracic appendages, indicating that there 

 are thirteen corresponding segments; these, with the seven abdomi- 

 nal segments, iu thai there are twenty segments in a t \ j > n • .■ 1 1 



Crustacean. There is a pair of b talked movable c pound ■ 



The ears are situated in the smaller antennae (Fig. 94, o'). In the 

 Becondor larger antennae are situated the openings of the ducts 

 'J4, pleading from the "green glands," while the external openings 

 of the oviducts are situated, each on one of ill'' third pair of thi 

 : 

 It is impossible, except by counting the appendages themselves, to 

 tain witli certainty the number of segments in the cephalo- 

 thorax, the dorsal portion of the segments beii 

 lete, but the carapace, or shield of the head thorax, may be se u, 

 after close examination, to represent the second antenn I man- 



/;. 



flab 



i en, 



cjrp 





Fid. 96. — A, first maxilla of lobster; en, endopodite; ?'/>, basipoditp; /fab, flabel- 

 lum. B, second maxilla of lobster; hp, basipodite (epignathus); i 

 podite. 



dibular Begments, and is so developed as u> cover the other segments 

 of the head-thorax, the dorsal portions of which are undevelop d. 



To study the internal structure of the lobster, the dorsal 

 surface of the carapace and of cadi abdominal segment 

 should be removed; in so doing the soft inner layer of the 

 integument isdisclosed; ii is usually filled with red 

 menl cells. The heart lies under the middle of the cara- 

 pace; it is an irregular hexagonal mass surrounded by a 

 thin membrane (pericardium) with sis valvular opei 



Fig. 94.— .4, carapace; e, eyes; r, rostrum : a 1 , first pair of ant em 

 pair; h. outlet of green gland; m, man.lii.u-. and p, Itspali 

 ilia: in' 2 , second maxilla; mp, ftrsl maxillipede; rnp*. second maxillii 

 >»><'. third maxillipede: withep. enipodite, and ■:. gill; i <l. first leg 

 abdominal segments; Ef.telson; /» , flrsl pair abdominal legsol male: B 

 of female; D% section of abdomen, with en, endopodib 

 basipodito; S, section of eye; /, cornea; v, cooes; e. rod: n, brand- 

 mam optic nerve. 



