4 



Moulting takes place from time to time. It is done by the old 

 crust becoming brittle and breaking away gradually. The entire crust 

 is cast away in larval stages only. 



Swimming larvae of Penaeus are very widely distributed in shallow 

 waters. They are often found in waters shallower than the place 

 where spawning animals live. I have collected last summer different 

 stages of larvae from Naitpluis to the stage of young prawns. They 

 are very minute. In the Nduplius stage they are 1/4 — 1/2 mm. and 

 in the Zoea stage about 3/5 — 2 m m. Their motion in the water is 

 rather inactive. Larvae of some species in the Zoea stage have many 



bright pigment cells. These cells generally expand in the dark places 



Y 



and contact when exposed to light. Protozoea of some species have 



a pair of short spines or teeth at the anterior margin of the carapace, 

 just anterior to the rudiments of the compound eyes (PI. VIII, 4). In 

 another species I found two pairs of such teeth (PL VIII, 6). 



In the newly hatched A T cmplius, we find no cilia on the bristles of 

 the appendage (PI. VIII, 1). In the later stages of the Nauplius, the 

 body and some appendages are already segmented (PI. VIII, 2,3). In 

 the Protozoea stage the metastoma appears as a paired knob, just 

 behind the mandibles (PL VIII, 5). In the Metazoca stage bristles of 

 the first appendage are not ciliated. The simple median eye is found 

 in the young prawn stage too (PL VIII, 8). 



Most shore fishes feeding on the bottom are enemies of adult 

 prawns; and fishes like Clupeidae, Carangidae, etc. do much injury to 

 swimmino- larvae. 



•J At present I have 13 species of the genus Penaeus, all from; the 

 waters of our country. As the determination of species of this genus 

 is unusually difficult, I have studied a great many specimens in different 



