CHAP, xxii.] SUPPOSED CASES OF DOUBLE ANTENNA. 549 



I feel no certainty that they are so. Nothing but careful micro- 

 scopical examination can shew this, and it would in every case 

 be necessary to begin by fixing upon some definite character 

 differentiating the anterior from the posterior border in the 

 normal antenna. 



In the majority of cases one of the branches has less than the 

 normal number of joints. 



Special attention is called to No. 854, for in it is seen not only 

 an extra branch, but an extra joint in the course of the chief 

 antenna. 



N.B. At the end of this list I have set three cases of extra 

 antenna arising from the head. 



*854. Lucanus cervus (Lucanidae) : left antenna normal, practi- 

 cally same as that described for Odontolabis No. 799. Right 

 antenna shews a rare condition. Scape and 2nd joint normal. 

 Then follows a piece as long as the 3rd, 4th and 5th joints of a 

 normal, together. This joint has a complex form. It has no trans- 

 verse division and is clearly one segment from base to apex, but 

 the posterior border is divided from the anterior by an irregular, 

 crescentic suture, giving it the look of two joints spliced together. 

 The posterior portion gives origin to a small, backwardly directed 

 branch made up of two nearly spherical joints, the apical having 

 a minute depression whence a fragment may have been broken. 



The long third joint just described bears at its apex the rest 

 of the antenna, which is abnormal in structure and diverges a 

 little forward of the normal direction. In the normal there are 

 only 7 joints peripheral to the 3rd, making 10 in all; here 

 there are 8, making 11 in all. The four apical flattened joints 

 are normal, but the joint preceding them (7th in this antenna) 

 is more produced on the anterior border than in the normal, 

 and it is thus in form almost intermediate between a funicular and 

 a lamellar joint. The other three are simple funicular joints. 

 For this singular specimen I am indebted to the kindness of 

 M. Henri GADEAU DE KERVILLE. 



855. Nigidius sp. (Lucanidse) New Guinea : the second joint of 

 the right antenna bears a small supernumerary three-jointed 

 branch directed forwards and upwards. The terminal joint of the 

 branch, which morphologically stands fifth from the body, bears 

 a long hair of the kind which is borne in the normal antenna only 

 by the seventh and subsequent joints. 



There appears to be no deformation in the normal antenna in 

 correspondence with the presence of this extra branch. The posi- 

 tion of the antenna with reference to the second joint is a little 

 altered, but it is not in any other way changed. This specimen 

 was kindly lent to me by M. Henri GADEAU DE KERVILLE. 



856. Lucanus cervus : the second (1st funicular) joint of the 

 left antenna bears a four-jointed, pointed filament. The lower 



