306 WILLIAM A. HA SWELL. 



wards from near the middle of the ventral body-Avall ; the 

 fibres of the more posterior of these extend thi'ough the 

 appendage to its extremity. In the following segment are 

 two pairs of narrow bands of fibres which act as protractors 

 and retractors of the penis, running inwards from the lateral 

 body-wall, the latter in front of and the former behind the 

 third cirrus, and becoming inserted into the processes at the 

 base of the penis (figs. 1 and 14, pro. m., retr. m.). In the 

 same sex, in the interval between the second cirrus and the 

 clasper, a pair of bundles of fibres run nearly vertically 

 from the dorsal body-wall to the ventral, enclosing between 

 them a mesial space in which lie the alimentary canal on the 

 dorsal side and the nerve-cord on the ventral, with a portion 

 of the testis between. Further back again a similar pair of 

 dorso-ventral bands separate the alimentary canal, nerve- 

 cord, and penis, situated mesially, from the testes and 

 seminal vesicles at the sides. In the female a pair of bands 

 of the same character (fig. 11, m. oh.) occur in the region of 

 the anterior part of the ovary. In both sexes a strong band 

 of transverse fibres extends across between the fifth and the 

 following segments ; it does not seem to form a complete 

 partition. Throughout the body slender oblique bundles 

 occur at fairly regular intervals, running from the cuticle 

 of the lateral surface to that of the ventral near the nerve- 

 cord. 



The dorsal and ventral longitudinal bands both send con- 

 tributions of fibres to a pair of large flexor muscles (fig. l,Jl.) 

 Avhich run thi-ough the posterior leg on its anterior side, and 

 eventually terminate in the minute lobes at its distal end. 

 From the ventral longitudinal band a bundle of fibres runs 

 backwards and outwards to become inserted into the cuticle 

 about the middle of the ventral surface of the leg. A few of 

 the fibres of the extensor muscle run nearly transversely in- 

 wards as a narrow band which unites with the corresponding 

 baud of the opposite side. A narrow bundle runs obliquely 

 inwards and backwards from the angle between the leg and 

 the caudal region to the posterior median depression between 



