Embryology of the Phalangiide. 403 
towards the ventral surface, and opens into the urinary sac 
(figs. 34, 35, and 50, cow, cox). The latter (figs. 33, 34, 35, 
and 50—H/S, O. HS) extends a long way backwards into the 
abdomen, while in front it stretches beyond the point of 
attachment of the third pair of legs; with its anterior blind 
end it closely adjoins the bow-shaped bend of the terminal 
vesicle (fig. 50). Not far from its anterior end there issues 
from the urinary sac a tolerably narrow duct, which passes 
downwards and opens to the exterior between the coxe of 
the third and fourth pairs of legs (Loman) (figs. 33, 50— 
O. HS). It was impossible to examine the histological 
structure of the terminal vesicle more closely, since this por- 
tion of the gland was found to be ina rather bad state of 
preservation in the preparations. The structure of the tube 
(figs. 87, 38) did not exhibit any considerable deviations from 
the typical structure of coxal glands, as, for instance, it has 
been described by Lankester and others in Scorpio, &c. The 
wall of the urinary sac (fig. 36, surface view) consists of a 
membrana propria with small and a pavement epithelium 
with large nuclei; muscle-fibres were not found in it. The 
remainder of the chapter on the coxal glands is devoted to an 
analysis of the papers upon the coxal glands of the Arachnids, 
especially to a criticism of the views of Hisig *, according to 
which the coxal glands are homologous not with the nephridia, 
but with the sete-forming glands (“ Borstendriisen ”’) of the 
Annelids. J may sum up my own views as follows :—(a) the 
coxal glands ot Phalangium consist of three divisions—ter- 
minal vesicle, tube, and urinary sac; (5) the same divisions 
are found in the antennary glands of the Crustacea; (c) these 
three divisions are homologous with the three portions of the 
nephridium of Peripatus (and Annelids), with the funnel and 
terminal vesicle (in Per¢patus—in Annelids the adjoining 
portion of the ccelome), the tube, and the expansion of the 
latter at its distal end; (d@) the coxal glands of Limulus and 
Arachnids, as well as the excretory organ of the Zoéa of 
Eryphia described by Lebedinski f, and the antennary and 
shell-glands of the Crustacea are homologous with the nephridia 
of Peripatus and Annelids; (e) Hisig’s hypothesis as to the 
homology of the coxal glands of the Arachnids with the 
* Hisig, “ Die Capitelliden,” Fauna und Flora des Golfes von Neapel, 
xvi. Monographie, 1887, 1. p. 574 et seq. 
+ The “nephro-peritoneal sac ” of the Decapods according to Weldon 
(Weldon, “ ‘The Renal Organs of certain Decapod Crustacea,” Quart. 
Journ, Micr. Sei, 1891, vol. xxxii.) probably corresponds to an extraor- 
dinarily developed urinary sac. 
{ Lebedinski, “ Entwicklung von Eryphia spinifrons,” Zeitschrift der 
Neurussischen Naturf. Ges. in Odessa, Bd. xvi., 1889 (in Russian), 
. 
