BY EUSTACE W. FERGUSOX. " 25 



From Uyborrhynchus the present genus differs more widely; tlie arrangement 

 of the rostral and head tubercles is ditt'ereut, but the chief point of distinction 

 lies in the relation of the bases of the prothorax and elytra. In Aeantholophw< 

 the base of the prothorax is practically as wide as the space between the humeral 

 angles which are at the junction of the fifth and seventh interetices ; in Hyborr- 

 hynchiis, as in Anascoptes and allied genera, the base of the prothorax is measured 

 by the distance between the ends of the third elytral intei'stices. 



Subdivision of the Genus. — Jladeay in his jiaper subdivided the genus into 4 

 groups : — 



A. With simple tubercle o\er the eye. 



a. Three rows of tubercles on each elytron. 



b. Two rows of tubercles on each elytron and one or two post-humeral 



lateral spines. 



B. With compound tubercle over the eye. 



a. Two rows of tubercles on each elytron and under 4 lateral spinas. 



b. Three rows of tubercles on each elytron. 



This classification followed on the lines of the table given by G. R. Water- 

 house {I.e., p. 1, 1854) for the few species known to him. Waferhouse, however, 

 included in his table species that were afterwards placed in Cubicorrlninclius and 

 Hyborrhfinchns. 



Maeleay's arrangement is, however, by no means satisfactory, as, according 

 to his grouping, the first 3 groups each contained three to six species, while the 

 bulk of the species was placed in group 4 which thus included many dissimilar 

 species . 



In endeavouring to group the si)ecies together on a satisfactory liasis, 1 have 

 experienced great difficulty in deciding what should be regarded as primary cliar- 

 acters, and the arrangement now suggested can only be regarded as tentative. 

 The difficulties arise partly from the great variation in so large a genus, and 

 partly from siinilar characters being sometimes present in members of what are 

 otherwise remotely separated groups. This, in some cases, appears to be due to 

 convergence of characters, in otliers possibly to the reappearance of an ancestral 

 character. The simple or single form of the. supraorbital crests is an example of 

 the first ; in several groups there appears a tendency to the formation of a single 

 crest either by the complete fusion of two rami or by the suppression of one 

 ramus, while in other instances the simple fonii seems almost a primitive charac- 

 ter. As an example of what I have termed the reappearance of an ancestral 

 character may be cited the subapical emargination or notch on the intermediate 

 tibiae. This occurs throughout all the species of one or two groups, but also 

 occurs in perhaps one or two species in a group, the other members of which do 

 not possess this character. The notch also occurs in genera such as Sclemriniu: 

 and Talaurinii.s which are not nearly related to Acantholophus. 



While, therefore, there occur groups of species all the members of wliich re- 

 semble each other closely in general facies, it is not always easy to define the 

 characters or limits of such gi-oups. In the accompanying table of species, there- 

 fore, while endeavouring to arrange the species according to their evident affini- 

 ties, the characters selected for the purpose of the table are not always what I 

 v,-ould regard as of primary importance. 



The genus as a whole, however, falls readily into fwo sections. In the first, 

 the head is separated from the rostrum by the intercristal ridge; the prothorax 

 is produced above and ocular lobes are present. The greater niunber of species 



