78 Records 0/ /he Indian Museum. [Xol. XXII, 



of the frons in Cephal'jcschna compared with its relatively small 

 size in Cdiaeschna as sufficing to separate the two genera. 



Martin on the other hand employed rather the Selysian 

 character and finding that the deiitigerous plate of Caliaeschna 

 inicrostigma 2 was rounded and subdenticulate, appears to have 

 suppressed Ceplialaeschna for that reason. 



Unfortunately he does not appear to have used this character 

 in all his species of Caliaeschna. For example, had he done so, he 

 would surely have removed C. laidlaivi from the genus, since it 

 is stated by Forster to have a dentigerous plate like that of 

 Gvnacantha. 



Hence we cannot rely in every case on his generic determina- 

 tion. The venation certainly does not, so far as my knowledge 

 goes, support the view that all these species are congeneric. From 

 ])ublished accounts I find that the dentigerous plate is rounded 

 and subdenticulate or without denticles in the following : — 



Caliaeschna inicrostinnia, Schneider. 

 Caliaeschna acutijrons, Martin. 

 Cephalaeschna orbifrons, Selys. 

 It i- armed with two stout spines in 

 Cephalaeschna sikkima, Karsch. 

 Cephalaeschna ? sp. 



The venation is dense in C. orbifrons and C. aciitiiroiis : 

 ' moderate ' in C. inicrostigma ; and may be described as ' open ' in 

 Cephalaeschna ? sp. and perhaps in C. sikkima and C. masoni, Martin. 

 T'or C. lugiibris, .Martin, I have no data. I hazard a guess that 

 Caliaeschna will ultimately be restricted to C. niicrostigma, vSchneider, 

 that Cephalaeschna will contain the species orbifrons and aculifrons ; 

 whilst a new genus will be required for C . sikkima and for Ccphal- 

 iieschna .^ sp. Tiiis genus will perhaps include Caliaeschna masoni , 

 ]\Iartin. 



The following is a list of references to papers dealing with 

 Oriental species of the group. 



de Selys, " Synopsis des Aeschnines ". Bull. Acad. Bclg. (3), V 

 (1883). The genera Caliaeschna and Cephalaeschna defined. 



Karsch, ' ' Kritik des Systems der Aeschniden." Ent. Nachr. XVII , 

 1891, No. 18, pp. 273-290. Suggests a classification of the 

 Aeschnine genera based mainly on venation. 



Karsch, Etit. Nachr., XVII. 1891, No. 20, pp. 6-7. Cephalaeschna 

 sikkima, Karsch, de=cribcd. 



Forster, .'inn. Soc. entomol. Bclg. IJI 1908, pp 213-214. Cali- 

 aeschna laidlawi , Forster, described. 



Martin, Cat. Coll. Selys, Aeschnines, XIX, XX, 1909. New species 

 of Caliaeschna Periacschna and Austroacschna described in a 

 monograph of the whole subfamily. 



Ris, Supplementa Entomologica No. 5. June 1916, pp 55-.'i(^. taf. 2, 

 fig. 5. Caliaeschna (?) acutifrons, Martin, 9 described, 



Tillyard,' Journ. Linn. Soc, Zool., XXXIII, July, 1916. Cali- 

 aesch)i(i conspersa, Tillyard, removed to a new genus Dendrn- 



