54 Records of the Indian Museiun. [Vol.. XIII, 



"high" form^ were caught in the month of February, whereas 

 those of the "low" form, exclusively obtained in other localities 

 were obtained in the months of January, February, March and 

 April. 



Acetes erythraeus was described by Nobili from the Red Sea; 

 the specimens in the Indian Museum are from the following 

 localities: — 



•2^^ Market at Ennur, near Madras... N. Annandale. Few. 



5^-2-2. Backwater at Vizagapatain, Mad- 

 ras Pres. ... ... S. Kemp. Many. 



9^i^^ Puri, Orissa Coast ... •■• { ^"l"^ 



N. Annandale, 



Gaunter & S. Kemp. Many. 



^^ Mouth of the Prai R., opposite 



Penano- ... . N. Annandale. Four, 



^1S>^ Patani R., below town of Patani, 



Siamese Malay States ... ,, Few. 



The specimens from the Patani river were found in water 

 that was fresh at the time of their capture^ but in a situation 

 subject to tidal influence. Those from Puri were found in the 

 open sea in water having a specific gravity of about i"026o (cor- 

 rected). 



The distribution of the species, so far as known, may be given 

 as, — Red vSea, west side of Bay of Bengal, Penang, Gulf of Siam. 



Acetes insularis, sp. nov. 

 (Text-figs, if,g, 2c, 3c, 4c, 5&,e, 7c.) 



The eyes are about one-third the length of the carapace and 

 do not differ in any marked degree from those of A. erythraeus. 



The basal segment of the antennular peduncle of the female 

 .s about I J times the length of the two ultimate segments com- 

 bined; the second segment is about 3-| times, and the third from 4I- 

 to 5 times as long as broad (text-fig. ig). In the male the second 

 segment is rather stouter than in the female, not more than 2 J 

 times as long as broad. The third is greatly lengthened, longer 

 th'an the first and from 9 to 10 times as long as broad (text-fig. if). 



The outer antennular flagellum of the male bears two clasping 

 spines in place of the single one found in A. indicus and A. 

 erythraeus; one spine is larger than the other, and the inner mar- 

 gins of both are smooth. The two basal segments of the flagellum 

 are short. There is also a curious apparatus not met with in 

 any of the other three species. The segtnent in advance of that 

 which bears the two large spines bears, on the side remote from 

 the spines, a large angular process pointing backwards and, on the 

 same side, behind the proximal end of the same segment are two 

 small spinules with their tips directed forwards. Judging from 

 their appearance these structures form a subsidiary clasping 

 apparatus that comes into action when the main grasping organ 

 is opened to its fullest extent. The segments opposite the tips of 



