64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IIO 



Mundoffnung enthaltendes, ringsum geschlossenes Gebilde entsteht." 

 The simple structure of the capitulum in adult Notostigmata (fig. 

 23 A), as described by With (1904), is quite in accord with Reuter's 

 account of the development in Pediculopsis. 



Analyzing the capitular structure on a basis of comparative anatomy, 

 Schulze (1932, 1935) contends that various elements besides the 

 pedipalp coxae and the cephalic lobe enter into its composition. First, 

 from a general study of the leg coxae of Ixodidae, Schulze deduces a 

 concept of a primitive ixodid coxa (fig. 22 C) having an anterior 

 process (/) projecting mesad of the trochanter {t), and an auricular 

 lobe {au) on the outer angle. Along the anterior margin of the coxa 

 a pleural fold, the "cymatium," is partly united with the coxa, but 

 distally projects as a "processus cymatii" {pc) at the base of the 

 anterior lobe. On the part of the cymatium adnate on the coxa is a 

 porous area {a) of sense organs like those on the areae porosae of 

 the capitulum. A small accessory fold {s) lies above the cymatial 

 process. 



The composition of the capitulum according to Schulze (fig. 22 D, 

 E) is as follows: The pedipalp coxae ("Maxillae") form the major 

 part of the basis capituli (Collare, or Kragen), but the trochanters 

 must usually be included, since in certain ticks they appear as distinct 

 basal segments of the palps (fig, 26 E, t). On the dorsal surface of 

 the capitulum (fig. 22 D) the areae porosae (a) are derived from 

 dorsomesal extensions of the porous areas of the coxal cymatia (C, a) 

 united along the midline of the capitulum (D), while the small tri- 

 angle {k) between their divergent anterior ends is formed from the 

 primary cephalic lobe. On the ventral surface (E), the coxae {c, c) 

 are united with each other proximally, but they embrace distally a plate 

 (//) representing the deutosternum, which bears characteristically 

 a pair of setae, and tapers distally in an "Unterlippe" {u) that forms 

 the median basal part of the hypostome ("Clava"). The lateral 

 toothed parts of the hypostome (/) are the anterior lobes of the 

 primitive coxae (C, /) united with each other distally and with the 

 sternal tongue between their bases. At the base of each coxal lobe 

 of the hypostome appears the processes cymatii (E, pc), and laterad 

 of this is a saddlelike piece, the "sella" {s), representing the small fold 

 above the cymatium of the primitive coxa (C, s). Finally, a sub- 

 coxal component is present as an invaginated extension from the base 

 of the capitulum (D, E, sc). Schulze concludes with a tribute to the 

 ingenuity of Nature, in that so many diverse parts can be brought 

 together to form a unified structure for a specific purpose. We can 



