, 506 ANALYSIS. 



bus cum tibia articulatis seu mobilibus. Tibiae anticse ex- 

 tus quadridentatae intus serrulatse tarsis nullis. 



Mnematium mihi. 



Ritchii f. 20. SCARABiEUS nigronitidus, capite punctata vertice depresso, 



thorace laevissimo punctata, elytris atris subsulcatis. 

 Habitat in Africa boreali. Mourzouk. D. Ritchie, Mus. Brit. 

 M. S. Perlustratoris intrepidi, zoologize peritissimi, amici nunquam 

 nimis deflendi, Joseph i Ritchie, quilaborcet curis defessus 

 sub sole Africano juvenis occubuit die Octobris vicesimo 1819. 



The only specimen known of this interesting insect is now 

 in the British Museum, and formed part of a curious col- 

 lection sent home by my lamented friend, the late Mr. 

 Ritchie, who, amid the versatility of his genius and know- 

 ledge, was particularly devoted to the science of entomo- 

 logy. The ScarabcBus Ritchii is one of the most con- 

 vincing arguments that can be adduced for the probabi- 

 lity of the chasms which now occur in entomology, being 

 all in due time filled up by the discoveries of travellers. 

 Until this insect was detected, there was a wide distance 

 between the S. sacer and S. JEsculapim of Olivier : but 

 now the chain of connexion is complete, as we have here 

 the clypeus of one species, with an approximation to- 

 wards the singular form of the other. Mr. Kirby long 

 since observed to me, that S. laticollis, semipunetatus, and 

 •oariolosus, quit the character of their type in having the 

 fore tibiae serrulate on the inside, the calcaria distinctly 

 articulated with the tibiae, the four hinder tarsi inserted in 

 the middle of the tibise, and the ungues rather long. Now 

 these are all characters which, to say nothing of the sub- 

 circular form of their abdomen, show us how these insects* 



