242 BULLETIN: MUSEUM OF COMPARATIVE ZOÖLOGY. 
*Mesostoma viviparum SILLIMAN. 
Mesostoma viviparum Sıruıman, Zeitschr. f. wiss. Zool, Bd. XLI. p. 59, Taf. TIT. 
Figs. 1-5, 1885. Girarp, Ann. Sci. Nat., Zool., Tom. XV. p. 218, 1893. 
Woopworrn, Bull. Mich. Fish Commission, No. 8. 1896. 
“Old Channel, Round Lake, Charlevoix,:on alge, July 13, 1894. Length, 
when swimming, 0.75-0.80 mm., breadth 0.10-0.15 mm. Rounded anteriorly, 
pointed at posterior end. Pharynx just anterior to centre. Each individual 
contained 5-7 living embryos 320 X 128 p, which were easily set free when the 
parent was crushed by pressure of cover glass. Bach [embryo] has at centre a 
prominent circular pharynx 90 p in diameter. Color of adult deep grass-green, 
with lighter areas of globular shape. Zoöchlorelle (5 a in diameter) most 
abundant in front of the pharynx. Lighter areas are the embryos, in which 
the zoóchlorelle are not so numerous. Color and shape of the embryos the 
same as the parent." 
The above description differs from that of Silliman, who states that at the 
anterior end the animal is * etwas verschmálert und hinten abgerundet." It is 
difficult to account for such a discrepancy. 
*Vortex armiger O. Souw. 
Vortex armiger O. SocHMIDT， Zeitschr. f. wiss. Zool., Bd. XI. p. 25, Taf. IV. Figs. 
8,9, 1862, SiLLImaN, Zeitschr. f. wiss. Zool., Bd. XLI. p. 67, 1885. Woop- 
WoRTH Bull. Mich. Fish Commission, No. 8. 1896. 
Vortex similis GxgARD, Ann. Sci. Nat., Zool., Tom. XV. p. 209, 1898, 
One specimen, * New Baltimore, Lake St. Clair, Aug. 8, 1893. Trans- 
parent, very pale, brownish gray; intestine green. Anterior end truncated, 
slightly narrower than middle. Body converging toward posterior end, not 
[terminating] with a point but [with] an indefinite irregular bunch of digitate 
processes. Pharynx large, cask-shaped. Two reniform black eyes. Egg 
chestnut-brown, Very active." 
*Vortex bilineata, sp. nov. 
Vortex sp.? Woopwonrm, Bull. Mich. Fish Commission, No. 8. 1896. 
* Round Lake, Charlevoix, dredgings from old channel, July 20, 1894. 
sength 0.96 mm., breadth 0.24-0.32 mm. Anterior end truncated, posterior 
end pointed. Pharynx dolioliform, in anterior third of body, traversed by 
two prominent, lateral, nearly longitudinal bands of light chocolate brown, 
and numerous other pale, indistinct longitudinal lines. Zoóchlorelle in cen- 
tral part of the body, posterior fifth free from them, transparent brown. Egg, 
dark chocolate, 120 u x 80 u.” 
