36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 95 



thin, flexible sclerotic bands, best developed in the female (D, b, h). 

 A pair of large branched glands open into the dorsal wall of the 

 chamber a short distance behind the gonotreme (fig. 12 A, Gld). 



The female genital organ, or ovipositor, of Liobnniim is an elongate, 

 continuously sclerotized, flask-shaped structure (fig. 13 D, Ovp), 

 widest in its proximal half and tapering forward to its flattened distal 

 end, which bears a small terminal spine (a). The expanded basal part 

 of the organ is occupied by two masses of muscle fibers (figs. 12 A, 

 13 D, mcl) that converge distally from the lateral walls to their inser- 

 tions on a long stalklike apodeme {Ap) arising from the ventral wall 

 near the apex of the organ. The base of the ovipositor is deeply 

 emarginate dorsally and ventrally. The dorsal emargination is entered 

 from above by a slender duct (Dct) that proceeds from an elongate 

 bulblike structure lying on the dorsal wall of the genital chamber 

 (fig. 12 A, Bej), and is itself continuous anteriorly with the median 

 ductus conjunctus (Den) from the ovaries. The bulb and the duct of 

 the ovipositor are clearly ectodermal structures, since they have a 

 strong cuticular lining. The bulb, bulbus ejaculatorius of Rossler 

 (1882), is merely the upper end of the duct surrounded by a thick 

 layer of circular muscle fibers ; beyond the bulb the duct becomes an 

 extremely fine cuticular canal without a muscle sheath, traversing the 

 ovipositor to the base of the terminal spine, where it appears to open 

 on the under surface of the latter. In some of the phalangids one or 

 more pairs of small pouches diverge from the outlet duct just behind 

 its opening ; these pouches are said to be the sperm receptacles, but 

 they were not observed in the species here described. 



The genital organ of the male phalangid (fig. 13 B, Pen) has the 

 same general structure as the ovipositor of the female, but in Liobu- 

 num it is much slenderer than the ovipositor, and in two species ex- 

 amined its distal part is decurved or hooked (figs. 12 C, 13 C, Pen). 

 In the specimen shown at C of figure 12 the penis is exserted by a 

 complete evagination of the walls of the genital chamber (GC). 

 The initial act of protraction, it would seem, must be caused by a 

 contraction of the long anterior muscles of the penis (fig, 13 B, pincl) , 

 but in the fully exserted condition these muscles extend anteriorly 

 to the base of the penis from their origins on the postgenital sternum. 

 It is evident, therefore, that the final stage of protraction results from 

 a general compression of the abdomen that everts the genital cham- 

 ber. Retraction then must be brought about by the contraction of the 

 reversed anterior muscles acting at first in cooperation with the greatly 

 stretched posterior muscles (pmcl), which finally alone complete the 

 process. 



