Mangan — On the Mouth-Parts of some Blattidce. 5 



The galea {get) consists of two segments, a basal portion continuous with 

 the stipes and articulating by a well-marked joint with a distal hood-like 

 segment. The lacinia (la) is posteriorly decidedly segmented off from the 

 plate of the stipes, with the exception of its outer corner, which at m sends 

 back a connecting plate. For a little distance the lacinia is united to the basal 

 segment of the galea, the two appearing to move as a whole upon the stipes, 

 with some degree of backwards and forwards motion, but with no lateral 

 freedom. The lacinia ends in two strongly chitinized prongs, and along its 

 inner edge bears several rows of stiff setse. Just below the tip there is a 

 singular process {pr, fig. 3), which arises anteriorly from the inner edge; 

 although mentioned by RoUeston ('88), it is not recorded on any drawing of 

 orthopteran maxillae known to me. It is present to my knowledge in 

 P. australasicB, P. americana, and B. orientalis. In Phyllodromia germanica 

 it differs ; the two processes [pr, fig. 4) which in that species occupy an 

 exactly similar position being doubtless homologous with it. They resemble 

 curved setae for the outer portion of their length, but, broadening basally, they 

 merge gradually into the surface of the lacinia without exhibiting any of the 

 thickenings or constrictions peculiar to the articulation of hairs. The above 

 projections are probably homologous with some of the terminal processes to be 

 found on the lacinia of forms like Machilis. They certainly correspond with 

 the " comb-processes " on the lacinia of the Lepismatidte (Escherich, '05). 

 Their condition in the Japygidse (Verhoeff, '04j is intermediate between 

 their condition in the Machilidse on the one hand, and in the Lepismatidss 

 and Blattidse on the other. 



The cardo is lowered by a tripartite muscle, which has its origin on the 

 under surface of the tentorium, at the side of the central keel, a bundle of 

 fibres ( W) being inserted at the base of the stipes, and also ( W) on the outer, 

 and ( W") on the inner segment of the cardo. The same arrangement exists 

 in Forficula (Verhoeff, '05), and I think it supports the idea that the cardo is 

 not, as usually stated, a single segment. The cardo is raised, or abducted, by 

 a muscle (P) inserted in front on a slight process of its inner sclerite. This 

 muscle arises in two distinct portions from the posterior region of the epi- 

 cranium. The stipes is adducted by a powerful muscle, inserted upon an 

 internal chitinous ridge which extends along the posterior inner edge of that 

 segment. This muscle has its origin, in part {G) upon the keel of the ten- 

 torium, in part {G') lower down upon the central plate. The smaller portion 

 {G') probably assists in raising the cardo. The stipes is apparently restored 

 to the vertical by the elasticity of the liinge between it and the cardo. The 

 same internal ridge of the stipes gives purchase to the two muscles D and 

 E which move the basal segment of the palp, the succeeding segments being 



