Mr. Kirsy’s Defériptions, &c. 317. 
fide furround the ovary, behind which they unite again, and ter- 
minate in a point at the tail. : 
'The ovary itfelf is of an oblong form, and generally MEA at 
the ends, In it are ufually two fpots which have a luminous 
appearance. It contains three or four roundifh eggs *. 
This fpecies affumes a variety of forms: when at reft it is 
famiewhat ovate, but when in motion it becomes linear. | 
The margin is white, and very tranfparent, affording an elegant 
contraft to the interanea. At reft it is ufually crifped, and fre- 
quently exhibits the appearance of many angular projections. 
Thefe are fometimes reduced to four, of which two form a kind 
of hunch, one on each fide, juft below the head, and two juft 
above the tail, which gives the little animal a very fingular form. 
At other times its contour is indented by jé finuofities. 
fo contracted 2 ar Tt: nisu 
When in motion it is ; ufually t between fix and rn lines in 
length, i 
Found amongft the Lemna gibba, in the Autémns in a “flow 
ftream. 2 
2. H. NIGRA. 
H. depreffa nigra lincaris abdomine nigro. 
Defeription, ‘This fpecies is entirely black, of a deep rich cou 
like velvet, except that juft above the tail there i is operi à femi- 
pellucid fpot of a whitifh caftt. Me TP 
# Upon examining one of thefe eggs fub lente, I difeoyeted two black points upon it 
exactly, fimilar to the eyes of the old one: whence perhaps it was a axé and this nie 
cies viviparous. 
+ The whole worm, when kept long in water in a glas, ins’ to incline to an afh 
colour; occafioned perhaps by the want of its proper food, 
: |I never 
3 
