﻿208 BRITISH FOSSIL CRUSTACEA. 



laterally in the cephaletron. Parts of the ovary are single and median, the rest consists 

 ■of parial, symmetrical, lateral, ramified tubes, chiefly situated in the cephaletron. 



" The hindermost cavity (PI. XXXV, fig. 6 q) is a longitudinal tube, commencing by 

 a blind end above the rectum ; it extends forward, expands, and bifurcates about the 

 middle of the thoracetron ; the branches at first diverge, then bend inwards and reunite, 

 sending back into the interspace of the bifurcation a short blind sac. Prom the base of 

 this heart-shaped portion the bifurcate tubes are continued forward, slightly diverging, 

 leaving a mid-space for the heart and intestine, as they cross the articulation between 

 the thoracetron and the cephaletron. About two inches in advance of the second 

 bifurcation each tube expands laterally into a triangular cavity, from the outer and 

 fore angles of which the ramified systems of the lateral loops, q", are continued. A 

 small branch is sent off from the outer side of the dilatation. Three or four tubes 

 converge from its fore part, and anastomose 1 to form the anterior single symmetrical 

 cavity, q x . This is oblong, subquadrate, subdepressed, and subreticulate. It is 

 longitudinally channelled above by the fore part of the heart resting thereupon, this part 

 of the ovary being interposed between the heart and intestines (PI. XXXIV, figs. 1 

 and 2 q). It seems to have been developed in or from the last remnant of the 

 including germ-mass. From the hinder and outer angles of the antero-median part of 

 the ovary proceeds the tube, which passes outward and backward, joins that from the 

 fore part of the lateral expansion, and curves outward and forward to meet and inosculate 

 with a similar retrograde branch from the fore and outer angle of the antero-median lobe. 

 Prom the outer side of these ovarian loops (PI. XXXV, fig. 6 q") proceed four or five 

 branches, which interramify with the hepatic lobe. The branch tubes (q x ) continue from 

 the fore part of the antero-median sac, and its loops are continued, subdividing and reti- 

 cularly anastomosing, along the sides of the gizzard to the fore part of the cephaletron. 



" Each of the main parial oviductal canals, before converging to the anterior reunion, 

 dilates and sends outward and backward a wide tube, which, after sending off, or rather 

 receiving, three large tubes (q**), is continued backward as the common oviduct 

 (PI. XXXV, fig. 6 o, o). The hindermost of the three large tubes passes outward and 

 backward to near the outer ends of the joint between the cephaletron and thoracetron, 

 and there curves forward beneath the lateral cephaletral ridge, and receives the ova from 

 the part of the ovary extending to the lateral margin of the cephaletral cavity. The fore- 

 most of the three branches collects the ova from the deeper seated interapodemal parts of 

 the ovarium, the intermediate branch those from the dorsal level above and exterior 

 to the apodemata. 



1 "'Lectures on Invertebrata,' ed. 1855, p. 329, shown in Mam, in figs. 135, a', V . Anastomoses 

 between the right and left system of ovarian tubes were noticed by Gegenbaur (loc. cit., p. 247), who well 

 remarks on this evidence of crustacean affinity : — ' Durch diese Verbindung beider Ovarial half ten reiht 

 sich Limulus an viele andere Krustenthiere an, wogleichfals ein unpaarer Abschnitt der inneren Genital- 

 organe vorhanden ist.' " 



