MIDLAND NATURALIST. i$ 
accurate study is required before deciding whether Noctiluca 
Pacifica can be regarded as a valid species. 
The material at my disposal is not sufficiently well preserved 
to allow me to pronounce an opinion about the specific character 
of the Pacific Ocean animal, and moreover it is only by the study 
of the living specimen of such a delicate animal that one could be 
justified in giving a scientific opinion. The present paper was 
prepared partly for the benefit of those on the Pacific coast who 
are in a position of obtaining fresh material for study. Some 
fundamental data as to the structure of Noctiluca miliaris will 
be given and I leave it to others to decide whether Noctiluca Pacifica 
be a well grounded species. 
| F At one time Noctiluca had been placed among the Medusae, 
but a closer examination of the structure of the animal reveals to 
the microscopist the fact of relationship to the phylum of the 
unicellular Protozoa, and that it belongs tothe class of the Flag- 
ellata. Owing to its bladder-like appearance we would refer it at 
once to the Cystoflagellata as its proper order. Its name seems 
appropriate, meaning “night light," evidently referring to the 
property of producing diffused phosphorescence of sea water in the 
dark. This light is apparently produced by the layer of prote- 
plasm, situated immediately under the cuticle, and is caused by 
some process of oxidation. The light is by some said to be caused 
B Algae and diatom carapaces; (Food inclusions) in the proto- 
ined 
G. Buce alg e. F. Vacuoles t g wate 
H. Bundle gi pee Arabi ane the cher si inog the rod. 
I. Fat globules stained b with osmic acid. 
J. Central protoplasm PMCS numerous fat globules I, and 
nucleus, D. 
K. Mouth 
L. Bundle of reticular threads connecting the central protoplasm 
with the tentacle where they become transversely striated 
Fig. 3. Optical section of Noctiluca perpendicular to the specus = 
passing through tbe central protoplasmic mass secon eus. 
J. Central ie d qud B. Cell wall. F.Water Finaalis. e proto- 
plasmic threads 
Fig. 4. A small portion of protoplasm showing its structure as it appears 
just under the cell wall 
. Trabeculae of the reticulum. 
pees filling the spaces between the threads of the reticulum, 
the fat bodies, (Inclavata.) [Partly after Carnoy.] 
