THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 183 
Habitat.—Subcutaneous tissue of all regions of the body of Notropis 
megalops Raf. (red-finned minnow/ytaken in Black River, Lorain County, 
Ohio, 6 miles above Lake Erie, September 1, 1890 (also October 5, 1891; 
see below). Collector, Mr. L. M. McCormick. Identification by Dr. D. 
S. Jordan. 
With this species of fish were taken Noturus miurus, Catostomus teres, 
and Moxostoma macrolepidotum, and, in the immediate neighborhood, 
Ictalurus and Roceus. None of these, however, were affected. 
Effects —The epidermis of the fish is sometimes marked by dark 
purplish blotches. Scales are absent from the surface of the cyst in 
most cases, although a few were observed quite loosely attached to one 
of thelarger clusters. Allof the fishes appeared to be in fair condition. 
Mr. McCormick has kindly furnished me the following additional 
information: 
The fish were taken in the pool formed by Day’s Dam, near the center of Sheffield 
Township, Lorain County, Ohio. Although he has diligently explored the streams 
of Lorain County for material for his ‘‘ Descriptive List of the Fishes of Lorain Co nty, 
Ohio,” + he has never seen N. megalops infested by this parasite except in this very 
limited locality. The same day that specimens were first secured there he seined 
Black River thoroughly from Elyria to below Day’s Dam (distance 10 miles), but saw 
no other diseased specimens. Inspite of the admitted fallibility of negative results, | 
he believes this parasite to be restricted to a very narrow geographical range. Fish 
first taken September 1, 1890 (about a dozen); a few more October 5, 1891 (the first 
time of seining the pool that year). y 
13. Genus et sp.incert. Pl. 7, fig. 4. 
Psorosperms of Gasterosteus aculeatus, Lieberkiihn, 1854, Muller’s Archiy., pp. 
9-10, 22, 24, 354-7, pl. 2, fig. 28, pl. 14, figs. 9-12. 
The following observations by Lieberkiihn relate to a puzzling form 
found on Gasterosteus aculeatus (stickleback). His remarks are to me 
somewhat obscure, and I am not certain that I always understand 
his meaning. For that reason the translation is a literal one. 
[Page 9] Iam still in entire ignorance as to what becomes of the psorosperms of 
Gasterosteus. In the skin of this fish Gluge found cysts filled with entirely 
structureless granules which had a marked similarity to those of the Gregarines. 
Johannes Miiller has confirmed this discovery. Linvestigated about 100 cyst-bearing 
specimens selected from a corresponding number of healthy sticklebacks. Among 
10 fishes there was, in the spring, about 1 available; in late autumn, on the con- 
trary, only 1 in about 100. The cysts varied greatly in size; the largest attract 
attention at once, the smaller are only to be discovered upon close examination. 
They have a very irregular form, mostly rod-shaped, and contain ordinarily the 
Structureless granules mentioned by Gluge. A few contained bodies with more defi- 
nite structure and characters, reminding one of the psorosperms, for which reason 
I willso name them. They are all nearly globular and somewhat smaller than the 
ordinary psorosperms; they consist of a transparent membrane, within which I have 
observed 3 kinds of contents, namely, in some a single small globule which is not 
large enough to come in contact with the membrane by its upper surface; in others 
lay, between the surrounding membrane and the upper surface of this 
[Page 10] small globule, a small mass of exceedingly fine granules; in still others 
the globule appeared to have divided, as 3 or 4 smaller globules were 
present. Several of the smaller cysts contained afar more finely granular mass than 
1 Bull. 2, Oberlin College, Ohio, 
