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IV. — Trochosphsera (equatorial is, a spherical Rotifer found in 
the Philippine Islands. By Herr Semper. 
Plates CXX., CXXI., axd CXXII. 
It is well known that the farther we descend in the scale of animal 
life a gradual abolition of all climatic contrasts becomes apparent ; 
whereas among the higher animals these contrasts are exhibited 
in innumerable species and varieties. The Botatoria on the 
whole follow this rule. My surprise was therefore considerably 
heightened when in a very limited space on the Philippine Islands 
I discovered a specimen differing from all its kin in .the highest 
degree. The strange relations existing throughout its organiza- 
tion will perhaps justify a more minute description. 
This creature is found among worms (for the most part naids), 
copepoda, other rotifers, infusoria, &c. (all of which resemble the 
European forms more or less), in the fresh water of the ditches 
which surround and intersect the rice-fields of the plain of Zam- 
EXPLANATION OF PLATES CXX., CXXI., AND CXXII. 
Figs. 1 and 2. — Trochosphsera slightly magnified. Fig. 1 seen from the side. 
Fig. 2 as seen from the anal pole, a, mouth; b , mastax with jaws; c, brain- 
ganglion ; d, pharynx (oesophagus) with the two glands r ; e, stomach ; /, cloaca ; 
g, anus; A, ovary; i, oviduct; h, excretory duct ; l, muscle-layer; m, eye; nn, the 
two problematical lateral sense-organs ; p, middle nerve for the middle sense- 
organ o ; q, equatorial circular fringe. 
Fig. 3. — Section of mouth largely magnified, o, mouth ; m, pharyngeal muscle ; 
c, cilia of the equatorial fringe (not represented in front of the mouth to show the 
finer cilia of the buccal funnel) ; g, ganglion ; I and 2, nerves to the pharynx and 
front part of the equator ; 3 and 4, nerves to muscles, eyes, and sense-organ ; 
5, nerve of the excretory organ ; 6, unmatched single nerve of the sense-organ o. 
Fig. 4. — Muscle surface of one side, a, equatorial fringe ; 6, muscle-hollow 
along whicli the muscle surface l lies ; /, its passage into the aboral hemisphere ; 
3 and 4, nerves to the muscles ; 3 6, nerve to the lateral sense-organ ; 4 a and b, 
nerves to the eye and another ganglion-shaped organ (cp. Fig. 5). 
Fig. 5. — 4 a, nervus opticus ; a, lens of the eye ; 6, pigment covering of the 
eye ; c, ganglion opticum ; d, uncertain organ, final swelling of the nerve 4 b. 
Fig. 6. — Part of the equatorial fringe, where it is broken at a point immedi- 
ately opposite the mouth, a a', blunt ends of the circular fringe ; 6, its connecting 
bridge not ciliated ; n 6, middle nerve ; /, ganglion-like swelling belonging to it ; 
g, middle nerve to the sense-organ h with its final body i ; g g', nerves of the back 
part of the equatorial fringe. 
Fig. 7. — Organ of excretion, a, duct ; b b, the two glandular lobes ; c c, the 
two ciliated channels, which cross (or unite ?) at d\ c\ extreme end of the ciliated 
channel to nerve 5 ; n 3 b, nerve to the problematical lateral sense-organ c ; /, its 
extreme body. 
Fig. 8. — Jaws of the mastax. 
Fig. 9. — a, rectum ; b, contractile bladder ; c, cloaca ; d, stomach ; l, oviduct ; 
m, muscular band of the ovary ; o o, ovary ; n n\ excretory ducts. 
Fig. 10. — Cloaca and sexual organs with developed eggs, a, an egg in the 
cloaca; 6, egg in oviduct; c, oviduct; d, point of junction with the cloaca; 
l, rectum ; /, eggs in the ovary with star-shaped nuclei. 
Fig. 11. — A developed young Trochosphsera found in the cloaca of another 
specimen. 
