Memoirs of the Indian Museum. 



(Outer tubercles at least as far from one another as from anterior 

 angles of head ; never asymmetrical, except when lateral and inter- 

 mediate areas of metasternum are fusel ; surface of head usually 

 rough ; dentition always complete 

 ^' ' Outer tubercles at most as far from one another as from anterior 

 angles of heal ; often asymmetrical, always so when lateral and inter- 

 mediate areas of metasternum are fused ; surface of head smoother, 

 polished ; dentition complete or reduced 

 i Anterior intermediate and lateral areas of metasternum distinct 

 3. from one another 

 \ Anterior intermediate and lateral areas of metasternum fused 

 r Secondary scars feebly developed (sometimes absent), transverse, 

 j never extending back as much as half way to posterior margin of 



Imentum . . 

 Secondary scars distinct, variable 



Secondary scars represented by a pair of very small grooves, meet- 

 ing in an acute angle . . . . . . . . 



5.^ Secondary scars represented by a single long transverse crescentic 

 or semicircular groove, crossing middle-line about halfway between 

 anterior and posterior margins of mentuni . . 



I Anterior intermediate and lateral areas of metasternum distinct 

 from one another* ; dentition complete, normal 

 Anterior intermediate and lateral areas of metasternum fu-ed ; 

 dentition of mandibles reduced on both sides, but especially on 

 the left, anterior lower tooth (when present) widely separated 

 from middle lower tooth, and partially fused with lowest terminal 

 tooth 



[Vol. Ill, 



{Kciiif^ioloidcs Group) 3. 



(Protomococlus Group) 



[ Kiuipioloides, Gravely ']. 



{F.pisphowidc 



Kuwert']. 

 5- 



[Maslochilus, Kaup]. 



[Phiirnchilus, Kuwert ']. 



in which genus moreover, the dentition of the right mandible is always much more reduced than that 

 of the left. 



' These two groups are not very sharply separated. The asymmetrical species of the J'ro/niiiocochis 

 group can easily be recognized by the form of the anterior margin of the head (see Kuwert, 1S96, pi. vii, 

 figs. 70, 71, 77 and 82). Some of the symmetrical forms, however, come very near certain members of 

 the Kaupioloides group, but are smaller, with the upper surface of the head smoother and the middle 

 part of its anterior margin usually somewhat more prominent and never very broad. The genus 

 Kaupioloidcs. seems to be almost exactly intermediate between the two groups in the=e characters, but, 

 being itself very slightly asymmetrical, it is distinguished from all their symmetrical forms and many of 

 their asymmetrical ones by the fusion of the lateral and intermediate areas of its metasternum and from 

 the rest of their asymmetrical ones by the complete dentition of its mandibles. The lateral and inter- 

 mediate areas of the metasternum are also fused in all genera of the Ilypcrplcsthcuus group; in this 

 respect the genus Kaupioloidcs connects the archaic group in which I have placed it with this group, 

 which must in any case be supposed to have originated from some such archaic forms ; and in the 

 structure of the head it connects it with the members of the Protomococlus group. 



^ Mitt. Naturhist. Mus. Hamburg XXX, 1913, p. 103. 



■" Concerning the genera Episphenoidcs and Pharochiliis see also Heller, 1910, p. 17. The general 

 sliape of the scars of the ftjrmer is correctly shown in Kuwert's figure, but they appear somewhat 

 too sharply defined and at too great a distance from the anterior margin of the mentum ; so that the 

 effect is that of the form of mentum found in certain species of the genus Maslochiliis, rather than 

 of that characteristic of the genus Episphenoidcs. 



* The dividing line is less pronounced than usual in Auulnchcs schciikliiigi, Heller, but it is there; 



