Ann. Nat. Hist. (5) i. 1878, p. 101.
The antennae in the specimen represented were no doubt mutilated, though Westwood did not say so.
CR. Ac. Paris, xcviii. 1884, p. 832.
In his recent Insectes fossiles des temps primaires, pp. 373 and 396, M. Brongniart has himself removed this Insect to Protodonates. We shall again mention it when discussing that group.
Bactridium, though placed in this tribe, has only short antennae, of 20 joints.