19 



d, seen from above ; /, the liver-glands ; e, the stomach, with g, the wavy 

 moving intestine, around which the colorless blood circulates; h, the first 

 of the four abdominal segments on whose underside the four 

 pairs of rowing-legs can be seen ; p, of which only the left-sided 

 pairs have been drawn ; i, the so-called " genital segment." 

 The position of the genitals begins from the segment h, on both 

 sides of the intestinal part g, extending to the segment i, consist- 

 ing of very fine granulated, band-like glands, whose porus is on 

 the female on both sides of the segment i, also carrying in that 

 place the two egg bags ; K. The much smaller and more seldom 

 male-ones carry at certain times of the year the " Sperm ato- 

 phore, " an elongated, bag-like body on the middle under-side of 

 the segment g, which contains the products of the testicles, the 

 spermatic particles to fructify the eggs of the females ; l f the anus > 

 ra, the "furca," with the setaceous appendages n, magnif. about 

 60 — 65 diam. The wood-cuts represents a Spermatophore. 



Fig. V. — s, a young Cyclops with four legs (at a) around its mouth &., 

 the oval body d, magnif. 300 diam. Fig. V. — se, the same Cyclops in a 

 higher state of development ; b. the mouth, with the bag-like stomach ; c> 

 without anus ; a, the eight legs with setaceous appendages drawn around 

 the stomach, but not in favorable position for better showing the stomach — 

 several segments are developed ; d, the furca confounded with all other 

 segments at e, and /, the furcal-brushes. Magn. 250 diam. The Cyclops- 

 larva is generally called Nauplius, and undergoes five changes in their 

 development. (Carpenter.) The wood-cut represents a Nauplius 

 of a Cyclops. 



Fig. VI. — The Nais proboscidea (Annelide-worm) ; p, the 



tongue-like proboscis ; e, the pigmented eyes ; o, the oesophagus ; 



b, a muscular bag, in which the proboscis p can be retracted 



by the musculi retractores m ; the bag is furnished on both 



sides with four brush-like bodies; ch., the chitinous brushes, 



(cirri) arranged in four longitudinal lines along the body ; t, the 



chain-like stomach with dissepiments in constant motion for moving the 



colorless blood which surrounds it; i, the tractus intestinalis ; and a, the 



anus. Magn. about 30 diam. 



Fig. III. 88., shows the so-called ephippium, the egg- bag which the 

 Daphnia carries during the winter time; s, the horny, chitinous epi- 

 dermis of the bag, which is attached on the shields of the Daphnia by the 

 ligaments m. ; c, the glue-like mass in which the two hard-shelled winter 

 eggs are placed. 



Fig. IX. 7t., represents a piece of the Bryozoan Plumatella repens- 

 os, the mouth in the centre of the ciliated tentacles /, of which three are 



