82 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
lateral prominences bear ten (or sometimes nine?) similar styles. To right and left of the dorsal 
median prominence are two small bundles of very slender bristles. These take the place of the two 
large single styles in N. pelagicus. As is well known, such large single styles are often formed of 
cilia or small styles united in bundles; this is probably the case in N. p e lagicus, so that it is not 
surprising to find a large style in the one species corresponding to a bundle of small styles in the 
other. The buccal funnel descends directly from the lateral styligerous prominences; on its lateral 
walls are two elevations, each bearing five styles that project horizontally across the furrow through 
which the food passes. These correspond exactly with the two elevations in the buccal funnel of 
N. pelagicus (fig. 8) and with those described by Hudson and Gosse for N. brachionus. 
Thorpe (’93) has described as a new species Notops lotos, from China; the only difference between 
this and N. clavulatus is that the former has but three styligerous prominences on the corona, whereas 
Hudson says that “ N. clavulatus has a greater number of styligerous lobes” than N. brachionus, which 
he says has three (Hudson and Gosse, ’89, vol. II, p. 12). ' Hudson’s figure shows in N. clavulatus some 
six or seven or more of such lobes (vol. I, plate xv, tig. 3). But it is difficult to say how exact Hud- 
son’s figure was meant to be in this respect. From the figure it is not possible to say which structures 
represent styligerous prominences and which parts of the outer ciliary wreath, and the impression is 
given that the exact number and position of the prominences was not clear in the mind of the author. 
Such being the case, it has seemed most probable to me that my specimens are N. clavulatus, though 
but three large and two small ‘ c styligerous prominences” exist. Moreover, the two small prominences 
to right and left of the median one are very easily overlooked, and it seems to me possible that they 
were thus overlooked by Thorpe, and that his specimens were also N. clavulatus. Some exact informa- 
tion as to the corona of the typical N. clavulatus of Europe would be a valuable contribution from 
some of the European workers in this field. It is possible that such information may show that our 
form should be given Thorpe’s new name Notops lotos, but I think this highly improbable. In case 
this should turn out to be N. lotos Thorpe, it is worthy of remark that it was found here, as Thorpe 
found it in China, along with Trochosphaira solstitialis. 
23. N. pelagicus n. sp. (Plate 15, figs. 7, 8, and 9.) 
This interesting new member of the limnetic fauna of Lake Erie occurred rather sparingly in 
surface and bottom towings and plankton hauls from parts of Lake Erie in the neighborhood of the 
group of islands about Put-in Bay. 
On the first examination of this rotifer the generic affinities are puzzling. It has in many 
respects the general aspect of a Brachionus, seeming, like N. brachionus, to form a connecting link 
between the genera Notops and Brachionus. Its closest affinities are apparently with Notops brachionus 
Ehr., but with its partially loricated body it seems to resemble very closely also the Brachionus mollis 
of llempel(’96). Through the kindness of Dr. C. A. Kofoid, superintendent of the Illinois Biological 
Station, I have been able to examine the type specimens of Brachionus mollis. While the resemblance 
between the two is striking, Hempel’s species is clearly a Brachionus, while this is as evidently a Notops. 
The body is thick and clumsy, the dorsal surface rising in a regular arch from both ends to the 
middle (as seen in side view), the ventral surface nearly flat, but its posterior third sloping upward 
to join the dorsal surface (fig. 7). A ventral view shows a broad surface, widest some distance from 
the rear, thence narrowing suddenly backward to a blunt point (fig. 8). The coronal surface is so 
prone as to seem to form an almost direct continuation of the surface of the body. A short unringed 
foot with two inconspicuous toes completes the animal posteriorly. 
The integument is thickened to form a partial lorica, much as in N. hyptopus Ehr., to judge from 
the account given by Hudson and Gosse. In front the loricate nature of the integument is extremely 
evident, the dorsal edge having even four short teeth, as in species of Brachionus or Anurcea, while 
at the junction of the dorsal and ventral parts of the lorica there are in front two marked teeth or 
angles. The anterior ventral edge is nearly smooth, there being merely a rounded notch at its middle 
point. The corona can be partly withdrawn within the lorica, giving exactly the appearance of an 
Anurcea or Brachionus, with partly retracted corona — the edges of the lorica with its teeth standing out 
sharp and clear. Over the remainder of the animal the integument is merely stiffened, much as in 
some of the large species of Diglena, forming thus certain permanent folds. A pair of such folds 
extends backward from the head on either side, separating the lorica into dorsal and ventral portions 
(fig. 7). Just in front of the base of the foot a transverse fold passes across from one lateral fold to 
the other (fig. 8), seeming to set a posterior limit to the ventral plate. Yet the entire lorica, if it is 
to be so called, is pliable, not forming an unyielding shell as in the typically loricate Rotifera, and 
especially is the posterior region soft and yielding, so that there is no sheath or any indication of 
lorica about the place of attachment of the foot. Above the foot the body projects backward in a 
