13ß s. GOTO. 



1. MicrocotijU caiidata, n. sp. 



(PI. I, fig. 1 ; PI. II, fig. 7 ; PI. Ill, figs. 7, 8, 9, 10 ; 

 PI. lY, figs. 7 & 8 ; PI. V, fig. 3 ; PJ. YI, fig. 3.) 



Boilij '^ elongated, about 3.2 mm. in length, symmetrical. An- 

 terior suclicr with a membranous septum. G^nmon genital opening on 

 tlie same level as the beginning of the intestinal trunks ; atrial spines 

 conical and slightly curved, the longest measuring 0.01 mm. Ovarij 

 situated at about the middle of the wh(3le length of the b(jdy, with the 

 oviduct end on the right side, thence extending towards the left, 

 presenting a convex border in front. On being folded on itself on 

 reaching the left intestinal trunk, it turns again towards the right, and 

 on reachinii' its oviduct end takes a backward direction and ends at the 

 anterior end of the testes by being folded once on itself. The single, 

 median vagina is situated about six times as far forwards from the 

 anterior end of the ovary as it is behind the genital opening ; it leads 

 into a single, median canal, which, after proceeding backwards half 

 way towards tlie anterior end of the ovary, divides right and left 

 into two canals. These, the paired vaginal canals, after proceeding 

 backwards f<3r a short distance, become continuous w^ith the paired 

 yolk-ducts. The genito-intestinal canal takes its rise from the oviduct 

 exactly opposite the unpaired yolk-duct, and after proceeding for a 

 short distance backw.ards and towards the left side of the body, 

 suddenly turns towards the right, and finally opens into the in- 

 testinal trunk of the riniit side. The vitellaria of the two sides 

 are very distinct in front ; but posteriorly the. boundary between 

 tlie two can not usually be distinguished. The paired yolk-ducts begin 

 at about the end of the anterior third of the whole length of 



1). In this as in the following species, the curvatures of the body, when there are any, are 

 not taken into account. I would point out also that the lenyth of the body varies considerably 

 according to the different state of contraction, and that therefore much weight should not be 

 laid on it in the identification of species. 



