LOXOSOMA LOXALINA AND LOXOSOMA SALTANS. 135 
vacuole, wliicli is cleat’ and obvious. In the liver-cell there is 
no vacuole at all, the nucleus is large and splierical, rather less 
deeply placed, and the granules appear to be forming in the 
inner or more superficial part of the cells and to be accumu- 
lating towards the base. The difference in appearance seems 
to me to indicate the physiological difference between kata- 
bolic and anabolic metabolism. 
The curious pagoda-like arrangement of cells seen at the 
sides of the body of L. loxalina (fig. 6, k.) is probably excre- 
tory, and may perhaps be comparable in structure to the 
excretory orgatis described by Harmer for L. crassicauda, 
but the histological detail is insufficiently good for me to 
determine its exact nature. If it is so, the position would 
indicate an external opening on the side of the body just 
below the posterioi’ lophophoral ectodermic gland and not on 
the epistorne as in L. crassicauda, which is a considerable 
difference of position. It ma}^ be that the type of excretory 
organ described liere for L. saltans and in others, as, for 
instance, L. Davenporti by Nickerson, is derived from 
such a condition as the above, but it might have been 
correlated more closely with such cells as those known as 
leucocytes in the Ectoprocta, which have been shown by 
Harmer to have an excretory function. 
Reproductive 0 rgans. — 1 have seen no trace of a herma- 
phrodite condition sucii as Nickerson describes for L. Daven- 
porti, and which, 1 think, may occur in L. loxalina, though 
it is not possible to say that one individual may not produce ova 
at one time and sperm at another, as Harmer has suggested. 
It is possible that of my nine specimens of this species none 
was fully mature, but 1 do not think so. I find also that the 
gonad is single and median. In no instance have I seen a 
trace of a paired gland in either sex. Fig. 14 passes through 
the ovarian follicle of an individual which contains what 
appears to be a nearly fully grown oocyte. The follicle opens 
by a narrow duct into the atrium between the intestine and the 
epistorne (fig. 9, g. p.). The oviducts project so as to form a 
little papilla, which is seen cut across in fig. 9. I cannot find 
