70 MR. F. F. LAIDLAW ON THE [Feb, A, 



Calothemis biappendiculatus Selys. 



Calothemis biappendiculatus, Kirby, Oat. Odonata, p. 42. 



S . Length of abdomen 22 mm. Length of hind Aving 28 mm. 



Wings hyahne, slightly tinged with yellow at their bases. 



Pterostigma black, 2 mm. in length, covering 3 cells. 



Fore loing. 19 antenodals, the last continuous, 9-10 postnodals. 

 Discoidal triangle traversed, followed by two rows of cells. 2 supra- 

 triangular cross nerviiles, 2 cross nervules in the lower basal cell. 

 Internal triangle divided into 3 cells. 



Hind wing. 2 supra-triangular, 3 lower basal cross nerviiles. 

 Discoidal triangle traversed. 



Head. Lower lip yellow, ujjper lip black, eyes brown, occipital 

 triangle black, rest of head steely-blue black except a yellow mark 

 at the side behind each eye. 



Prothorax black. 



Thorax black above, dull brown below. Legs brown. 



Ahdomen. Segments 1 and 10 black, the rest bright red. Seg- 

 ments 2-3 with transverse carina. Segments 3-9 strongly 

 'triangular in ci-oss section. Rising from the bases of the genital 

 ramules are two long branches, standing at right angles to the 

 body. 



5 unknown. 



I took two specimens of this insect at Kwala Aring. They 

 differ from the type in having the upper surface of the thorax 

 rich black instead of brown. Otherwise they closely resemble it, 

 especially in the very remarkable genital organs on the second 

 abdominal segment. 



*Orchithemis pulcherrima Brauer. 



Orchithemis pulcherrima, Kirby, Cat. Odonata, p. 42 ; Kai-sch, 

 Abh. V. d. Senckenberg. Nat. Gesell. xxv. 1. p. 228. 

 Singapore {Ridley). Malacca [Selys). 



Diplacodes nebulosa (Fabr.). 



Diplacodes nebulosa, Kirby, Cat. Odonata, p. 42. 



A single specimen was taken at Kota Bharu, Kelantan. There 

 are specimens in the British Museum taken by Ridley in Province 

 "Wellesley. Widely distributed in the East Indies. 



Acisoma panorpoides Ramb. 



Acisoma panorpoides, Kirby, Cat. Odonata, p. 43. 



Kwala Aring. One specimen, (S . Tropical regions of the 

 Old World. 



Tetrathemis hyalinia Kirby. 



Tetrathemis hyalinia, Kirby, Cat. Odonata, p. 44. 



The two species of this genus which are represented in our 

 collection exhibit a very remarkable sexual dimorphism which 

 has not, I believe, previously been i-emarkod. The males have a 



