338 DR. A. E, SHIPLEY ON [ Mar. 16, 
latero-ventral rib, the second finger the antero-lateral rib, the 
third finger the medio-lateral rib, and the little finger the postero- 
lateral rib (PJ. XLIX. fig. 10). 
The spicules in the male are very conspicuous and very difficult 
to describe. Figures 11, 12, 13 on Pl. L. give a better idea of their 
appearance than any verbal description can. They are short, 
strongly chitinised, with thickened edges and a kind of haft or base 
at the anterior end; and each spicule is hollowed something like 
a crumpled, withered, lanceolate leaf. Each spicule is provided 
with retractor and protractor muscles, and, as fig. 12 shows, when 
protracted they are divaricated. When in this extruded condition 
they form a cross, the left spicule projecting to the right and 
vice versd. Besides the spicules and between them, rather to the 
posterior end, lies the accessory or median piece, which Looss calls 
the “gubernaculum.” It is best seen in profile, and has then 
somewhat the outline of a Turkish slipper. It also has muscles 
inserted into its ends. 
Near the base of each spicule is an oval clear vesicle, but 
apparently the end of the spicule was outside and not inside the 
lumen of the vesicle. 
The head presents very little signs of differentiation (Pl. X LVI. 
fig. 3). In some specimens with a one-twelfth objective three very 
minute lobes can be seen, but they are not visible in all cases and 
their appearance may be due to some expansion of the mouth. The 
mouth is terminal and leads into a slightly bulb-like cavity which 
soon narrows into the thin capillary lumen of the alimentary canal. 
The cesophagus is more granular than the intestine, and separated 
from it by a very shallow groove ; its walls consist of flatly rounded 
cells with conspicuous nuclei (fig. 5). I could not detect any parts 
in the intestine ; it appears to be an undifferentiated tube running 
from mouth to anus, the lumen lined with chitin and the walls 
formed of granular cells with visible nuclei. No food was seen 
in the alimentary canal. Posteriorly the intestine widens into a 
spacious rectum, which just in front of the anus narrows again 
into a short, thin, terminal portion. The anus in the male opens 
into the genital bursa; in the female it isa little distance in 
front of the end of the pointed tail, but relatively net so far forward 
as it is in the larva. Two cervical glands run about a fifth of the 
length of the body backwards, and end with rounded ends about 
the same level. 
In the male the testis begins about the level where these glands 
end. It consists of a single tube, the cells lining which give 
rise to the spermatozoa. Anteriorly the cells when squeezed out 
seem amceboid, with rounded and very refringent nuclei. The 
hinder end of the testis is, however, crowded with spermatozoa 
shaped like little squat bottles, and in some specimens the genital 
bursa sheltered two clumps of these, looking as though they had 
escaped from two vesicule seminales. 
I saw nothing of excretory canals or their opening, and unless 
an ill-defined ring which surrounded the alimentary canal, about 
