372 JOURNAL,BOMBAY NATURAL HISTORY SOCIETY, Vol.XVIH. 



The Appendages of the Head. 



To the parts of the antennse special names are given, the termina- 

 tion " pndite, " i.e., a " leg piece", being changed to "cerite" in Greek, 

 signifying a " horn piece " or feeler piece. 



In the case of the jaws the termination " gnathite", Greek for 

 "jaw piece", is often used, e.g., protognathite, scaphognathite, etc. 



The second maxilla is so overlapped by the first maxilliped as to 

 be almost concealed from view. It presents the appearance of two 

 thin plates, the inner of which is soft and membranous, its inner 

 margin fringed with hairs and divided into three serrations. The 

 proximal of these represents the coxopodite, the second, the 

 basipodite, and the third possibly the endopodite. The oilier 

 chitinous flap which lies under the cervical groove is the rapidly 

 moving paddle by means of which water is continually baled out of 

 the gill chamber. It is the epipodite probably united with the 

 exopdite. It has received the name scaphognathite from its boat- 

 shaped outline. The functions of this limb being mainly to assist in 

 respiration, its masticatory portion is uncalcified, feeble and 

 degenerate. 



The first maxillae are more obvious than the second in the living 

 animal, being more exposed and nearer the middle line. Each 

 resembles the Prince of Wales' crest in shape and is firm and well 

 calcified. The middle " plume," the largest, is the basipodite, the 

 inner, the coxopodite, both having a cutting edge set with stiff setae. 

 The outer piece is the endopodite, an oval plate fringed with short 

 soft hairs. 



In front of the maxilla? and looking like another softer pair of jaw 

 appendages is the metastoma (Gr. meta, behind, stoma, the mouth) 

 (Plate B, fig. M), which forms a soft lip and consists of one median 

 and two lateral lobes, the former being strengthened by two pairs 

 of small sclerites. 



Before removing the mandibles open and close them repeatedly to 

 observe the points about which they move. Note on the cleaned 

 skeleton that the lateral bulge of the carapace in front of the cervical 

 groove is almost filled by the outer portion of the huge mandible. 

 In front, of the mouth you will see a small soft flexible upper lip or 

 labrum, in which are two small symmetrical sclerites ; above this is a 

 small triangular space, part of the epistoma ; in front of it you will 



