FIG. 2.
FIG. 1.
In Plate XI., Fig. 1 exhibits the animal and vegetable living forms contained in Croton water. They have been catalogued as follows:—
(a) Asterionella formosa, vegetable; a diatom, × 312.
(b) Pediastrum simplex, vegetable; a desmid, × 200.
(c) Cyclotella astræa, vegetable; a diatom, × 200.
(d) Vorticella; an animalcule, × 312.
(e) Conferva, vegetable; “green scum,” × 40.
(f) Epithelial cell; × 200.
(g) Fragillaria cupucina, vegetable; a diatom, × 200.
(h) Heteromita ovata; an animalcule, × 500.
(i) Halteria grandinella (?); an animalcule, × 200.
(k) Anguillula fluviatilis; a water-worm, × 312.
(l) Amœba porrecta; an animalcule, × 200.
(n) Dinophrys; an animalcule, × 200.
(o) Didymoprium borreri, vegetable; a desmid, × 200.
(p) Tabellaria fenestrata, vegetable; a diatom, × 312.
(q) Free vorticella; an animalcule, × 200.
(r) Coccudina costata, dividing; an animalcule, × 312.
(s) Monas umbra; an animalcule, × 312.
(t) Cyclidium obscissum; an animalcule, × 312.
(u) Chilodon cucullulus; an animalcule, × 200.
(v) Epistylis nutans; young animalcules, × 200.
(w) Paramecium; an animalcule, × 200.
(x) Difflugia striolata, the lorica or case; an animalcule, × 200.
(y) Conferva; vegetable “green scum,” × 312.
(z) Vorticella microstoma; an animalcule, × 200.
(aa) Fragments of dyed wood, × 200.
(cc) Gomphonema acuminatum, vegetable; a diatom, × 200.
(ee) Arthrodesmus octocornis, vegetable; a desmid, × 312.
(ff) Scenodesmus quadricauda, vegetable; a desmid, × 200.
(ii) Navicula rhynchocephala (?), vegetable; a diatom, × 200.
Fig. 2 represents the organisms found in the Brooklyn (Ridgwood) water supply:—
(a) Actinophrys sol; an animalcule, × 200.
(b) Coccudina costata; an animalcule, × 200.
(c) Chætonotus squamatus; hairy-backed animalcule, × 200.
(d) Notommata; a rotiferous animalcule, × 200.
(e) Amœba guttula; an animalcule, × 200.
(f) Melosira orichalaea, vegetable; a diatom, × 200.
(g) Vorticella microstoma; animalcules, × 200.
(h) Chætonotus larus; hairy-backed animalcule, × 200.
(i) Tabellaria flocculosa, vegetable; a diatom, × 200.
The original drawings from which Plate XI. is taken were prepared by Mr. William B. Lewis, for the Metropolitan Board of Health.