The Anatomy of Opisthopatus cinctipes. 87 



The epithelium of the terminal appendage (fig. 29) of the gland is 

 also composed of cylindrical cells, but it is not so thick as the wall of 

 the middle region. 



The anterior pair of accessory glands {r.ac.g^ and l.ac.g^) is 

 much simpler in structure and consists of two long, fine, cylindrical 

 tubes of about the same diameter throughout and as thick as, or 

 somewhat thinner than, the efferent ducts of the posterior glands. 

 For a portion of their length, equalling that of the carrot-shaped 

 vesicle and its efferent duct together, the anterior glands lie free, but 

 their terminal portion, which ends blindly, is always irregularly 

 coiled in a single layer round the middle enlargement (r.c and l.c) 

 of the posterior glands. The coil always commences at the con- 

 striction between the middle portion and the carrot-shaped vesicle,, 

 while the blind end of the tube may lie anywhere on the outer sur- 

 face of the middle portion. The course of the coiled tube can be 

 followed without any difficulty in dissected glands (see fig. 16) and I 

 have ascertained with certainty from sections that there is no direct 

 communication whatever between the lumina of the two glands in 

 the region of the coil. A thin peritoneal covering (shown in fig. 25) 

 envelopes the coil, as well as the other portions of the glands. 



The sections through the right {r.ac.g^) and left anterior gland 

 {l.ac.g^) in fig. 25 will give an idea of the structure of the different 

 parts. The wall of the tube is formed of a simple epithelium of 

 cubical or somewhat flattened cells, and the greater part of the 

 lumen is occupied by coagulated secretion. It will be noticed that 

 the coiled portions of the accessory glands form a mass which is 

 considerably thicker than the carrot-shaped vesicles {r.v and l.v), 

 whereas in the dissected specimen (fig. 15) exactly the opposite is 

 the case. In reality the parts of both glands are about the same 

 size in the two specimens, with the exception of the carrot-shaped 

 vesicles, w^hich are three times as wide in the drowned specimen as 

 in the one preserved in spirits. 



Peripatoides. — In P. novcB-zecdandicB the accessory glands consist 

 of a pair of slender tubules with fine ducts, which discharge by 

 separate external openings situated at the ventro-lateral angles of 

 the body near the anus and therefore far behind the genital segment 

 (L. Sheldon, 1889) . In a specimen which I dissected these tubules 

 extended forwards up to the level of the genital opening, where they 

 are bent backwards or coiled about for a small portion of their length 

 and end blindly. 



According to Fletcher and Dendy (1895) a corresponding pair of 

 glands with their external openings in a similar position occurs in the 



