374 W. A. HERDMAN. 



ripe ova. They have the usual structure of uterine uephridia 

 in the Echiuroidea, and consist of (see fig. 26) (1) a simple 

 external aperture (nephridiopore)^ (2) a much-coiled slit- 

 like internal opening (nephrostome, n. s.), (3) a short wide tube 

 leading to (4) a globular dilatation {u.), in which the eggs lie, 

 followed by (5) a long, narrower csecal tube hanging down 

 posteriorly into the body-cavity. The eggs are chiefly in the 

 globular uterine dilatation (figs. 25, 26, and 31), and are very 

 distinctly seen through the transparent but rather tough 

 walls. The nephrostome is a striking object. The narrow 

 slit is drawn out to a great length to form two horns, 

 which are then each coiled up spirally (as shown in figs. 

 26 — 28), to form a structure closely similar to the dorsal 

 tubercle at the opening of the hypophysial gland in a Cynthiid 

 Ascidian. As in the case of the Ascidian dorsal tubercle, 

 however, there seems to be considerable individual variation. 

 My second specimen is not so much drawn out laterally, and 

 not so much coiled (see figs. 29 and 30). The external apertures 

 of the anterior nephridia (genital) are placed close together 

 near the ventral middle line of the body, and each is provided 

 with a strong genital seta, embedded in the body-wall and pro- 

 vided with special muscle bundles. These genital setae are of 

 a burnished golden appearance where they project to the ex- 

 terior. The shape is shown in fig. 13, and the entire length 

 of the seta is 5*5 mm. The inner end, which projects into the 

 body-cavity and has muscle bundles attached to it, is wider, 

 softer, and of a white colour. 



Gonad, &c. — Both my specimens were females. The ovary 

 in each case was distinctly visible, running along the upper 

 surface of the posterior part of the nerve-cord and ventral 

 vessel (figs. 17 and 18, ov.). A few ova were found floating 

 freely in the coelomic cavity, and, as has been noted above, the 

 anterior nephridia or uteri contained large numbers of ova. 

 The globular dilatation was in one specimen packed full (fig. 

 31), and in that case about 120 ova were visible on the one 

 side of the vesicle. The ovarian ovum not quite ripe has a 

 central more granular and opaque part, in which the germinal 



