904 



MB. H, H. BBINDLET ON THE KEGENEMATION [NoV. 30, 



The femur very frequently, and the tibia always, have a con- 

 spicuous armature of spines. The tarsus in all the Blattidae is five- 

 jointed. The proximal joint is the longest and stoutest, the next 

 much smaller, and the succeeding two very much smaller, while 

 the distal joint approaches the proximal in length and bears a 

 pair of claws. Between the claws mauy species haA'e a thin 

 rounded projection, the arolium. 



In other Orthoptera the number of tarsal joints is 3 in Forfi- 

 cuhdse, Hemimeridse, and Acridiidae, 2 or 3 in Gryllidae, 4 in 

 Locustidse, and 5 in Mantidae and Phasmidae'. 



The occasional occurrence among Blattidae of tarsi possessing 

 only four joints, but in other respects normal, has been noted by 

 entomologists from time to time. 



In the last century Geoffroy ^ specially characterized the genus 

 Blatta as having four joints in the tarsi of the posterior pair of 

 legs and five in those of the other pairs, though, in spite of this 

 statement, he figures both sexes with five-jointed tarsi on all the 

 legs. His description was doubtless based on one or two abnormal 

 individuals. 



This error was corrected by Ser\ ille ^ who does not allude, 

 however, to the occasional occurrence of abnormal tarsi. 



A few years later Brisout de Barneville '' called attention to the 

 occasional presence of four-jointed tarsi in several species of 

 Blattidae. He gives the following table, in which, as elsewhere in 

 this paper, I have followed the nomenclature of Brunner ' : — 



^ Brunner Ton Wattenwyl, ' Prodr. Europ. Ortbop.' 1882. 

 ' ' Hist, abregee des Insectes,' 1764, i. p. 379. 

 ^ Hist. nat. des Insectes, 1839, p. 58. 

 * Ann. de la Soc. Entoin. 1848, ser. 2, vi. Bulletin, p. xis. 

 ' 'Nouveau Systeme des Blattaires,' Vienna, 1865, and " Envision du Sjsteme 

 des Orthopteres," Ann. Mus. Genova, 1893, s6r. 2, xiii. * 



