374 JOURNAL, BOMBA Y NA TURAL HISTORY SOCIETY, Vol XVIU. 



only three large basal joints. The two distal belong to the 

 endocerite. The first movable joint has no opening for the 

 green gland. This opening you will find on each side on a 

 prominent little nipple near the outer angle of the large some- 

 what triangular plate in front of the epistoma. You find dorsally 

 behind the antennules and in front of the eye a large plate which 

 you do not find in the Lobster, Cray-fish or Prawn. Hence you are 

 driven to the conclusion that the coxocerites of the two antennae are 

 firmly fused together and that these two plates represent the dorsal 

 and ventral surfaces of the united coxocerites, and therefore the first 

 movable joint is the basicerite. 



Though we have for convenience numbered the antennules as if 

 they were the appendages of a somite, they really beloug to the 

 prostomium. Those who hold the contrary view believe the sternum 

 of the " antennulary somite" is fused with the coxocerites of the 

 antennae. The stem of the antennule, you will note, consists of three 

 cylindrical segments, which therefore do not correspond to the pieces 

 of the protopodite, only two in all the other appendages. 



The basal segment is the largest. There are two rows of setae on 

 its inner and dorsal surfaces. At the proximal end of the dorsal 

 surface is seen the auditory opening. Both filaments are annulated 

 and much longer in the Indian than in the European members of the 

 family. The inner filament is the longer. 



The eye-stalks or ophthalmites have each, two segments movable on 

 one auother. They are articulated to a median oval membranous 

 space which looks directly upwards. In this membrane are two 

 small median sclerites, one in front of the other behind the 'insertion 

 of the eye-stalks. Those who claim an ophthalmic 3omite would call 

 these the ophthalmic sternum and tergum respectively. They are 

 sometimes united to form a single piece. 



CIRCULATORY ORGANS. 



To examine the heart and greater vessels cut with stout scissors 

 along the outer side of each branchio-cardiac groove. Join these 

 cuts by a transverse one along the cervical groove. Remove the 

 calcified portion. Note the underlying skin spotted with red and 

 yellow pigment. Remove this skin carefully, and you will have 

 opened into a large cavity filled with blood, the pericardial sinus (Gr. 

 peri, around, kardia, the heart). 



