PACKARD.] KEPRODUCTIVE HABITS OF BEANCHIOPODIDJE. 421 



abdominal segment; it broadens rather suddenly, and reaches up in the 

 form of a whitish tape to near the middle of the united genital segments, 

 where it expands and suddenly contracts again into a more cylindrical, 

 narrow string, the vas deferens, for but a short distance, after which 

 follows a second larger expansion, representing the seminal vesicle, 

 bending knee-shai)ed down and outward, and after again narrowing to 

 a tubular ducr, the ductus ejaculatorius, is iuterrui^ted several times 

 with what I take to be accessory glands, just before entering the termi- 

 nal extensile portion, the complicated muscular apparatus. The cirri 

 are non-perforated, and supplied with minute booklets (as in Branch- 

 ipus grubei and B. stagnalis). At its base several powerful muscles 

 insert themselves, the musculi retrahentes. 



The anterior (upijer) end of the testicle is in younger individuals 

 of the red Eubranchipus and pale race A an obliquely cut-off tip, as 

 Spangenberg^ figures it in BrancJiipus stagnalis, but in set B no trace of 

 this prolongation, either in younger or older individuals, can be seen, 

 thus resembling Dr. F. Leydig's figure.^ 



The complicated muscle-apparatus, described and figured by Dr. H. 

 Nietsche^ {Branch, grubei), occurs also in Eubranchipus and its pale 

 races, the cirrus being likewise non-perforated and hooked. Chitinou 

 j)apilli {Branchi/pus grubei) and spines {Branchipus stagnalis) I could not 

 observe. 



(2.) Female organs (pale). — The spirally-wound ovary extends in setB 

 (and A?) not only with its posterior end into the penultimate post-ab- 

 dominal segment (as in red Eubranchii)us, Branchipus grubei and B. 

 stagnalis), but also with the anterior (upper) end up to the limit of the 

 fourth last pair of branchipeds.* 



I have often observed in living specimens from 5 to 6 plasmatic eggs 

 of a turbid white color in the upper ovarial string, but then the post- 

 abdominal section on the same side was empty, or the reverse. I also 

 occasionally observed both sections, the anterior and posterior, full of 

 jjlasmatic eggs, and at the moment ot entering the oviduct by jerks from 

 the posterior section, the anterior portion of the ovary remained filled 

 for some time until also emptied into the oviduct. The emptying of 

 the anterior section usually took place also on i)utting live si3ecimens 

 into alcohol, and in this instance the posterior portion remained filled. 

 The eggs of the anterior section have the same form and appearance as 

 those of the posterior. 



Another notable fact is a very short, transverse, tubular anastomosis 

 within the sixth and near the seventh post-abdominal segment. This I 

 have not seen to occur in the females of red Eubranchipus, neither have I 

 found it in all females of the pale races. The anastomosis^ passes 

 binder (ventrally) the intestinal tract, and is sometimes filled with 2 or 3 

 plasmatic eggs. It is about 1,^™"^ long, narrower than the lateral ova- 

 ries ; its skin apparently muscular, since the eggs are squeezed side- 

 ways out into the lateral strings when live specimens are placed in 

 alcohol, or when, by a jerk, the eggs enter the oviduct. 



1 Zar Kenntniss von Branchipus stagnalis von Dr. Friedrich. Spangenberg, mit Tafel 

 I-III. Zeitsch. f. wiss. Zoologie, xxv; Supplemeu theft, 1875, Fig, 28, t. 



" Dr. Franz Ley dig, * ' Ueber Artemia salina und Branchipus stagnalis." Zeit. f. wiss. 

 Zool. iii, 1851, Taf. VIII. 



3 Dr. Heinrich Mtsche, "Ueber die Geischlechtsorgane von Branch. Grubei von Dy- 

 bowsky" in Zeit. f. wiss. Zool., xxv, page 281, Taf. XXII. 



■• Schmaukewitsch doubts whether or not some of the branchiped-bearing body-seg- 

 ments beloug to the post-abdomen. The peculiar arrangement of the ovary here seems 

 to give support to this assumption. See Zeit. f. wiss. Zool. 1875, pages 114 and 115; 

 also Spangenberg, in op. cit. pages 8 and 9; and Nietsche in o}). cit. 



5 This anastomosis indicates a sexual relationship with certain Schizopod and Cope- 

 poda. 



