83 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
M. lata Jennings. — Lake St. Clair ( Jennings ’94). West Twin Lake near Charlevoix, Mich. 
(Jennings, ’96). Sandusky Bay, Lake Erie (Kellicott, ’96). Waters connected with the Illinois Kiver 
at Havana, 111. (Kerapel, ’98). This species has recently been found also by Stenroos (’98) in Finland. 
M. rattus Ehr. — New York (Ehrenberg, ’43). Near Minneapolis, Minn. (J. W., ’83). Near 
Cincinnati, Ohio (Turner, ’92). (Possibly the same thing was seen by Herrick (’85), who speaks of a 
rotifer resembling Monocerca rattus.) Sandusky Bay, Lake Erie (Kellicott, ’97). 
M. multicrinis Kellicott. — Sandusky Bay, Lake Erie (Kellicott, ’97). 
M. spinigera Stokes = M. bicuspes Pell. 
KATTULUS Ehrenberg. 
48. R. tigris Muller. (Plate 18, figs. 20 and 21.) 
In Naias, Put-iu Bay Harbor, Lake Erie. 
The animal described and figured by Gosse in the Monograph under the above name is apparently 
not Ebrenberg’s species at all ; my specimens seem to agree with those of Ehrenberg. Characteristic 
seems to be the curved body, not enlarged in front as is figured by Gosse, hut tapering gradually from 
about the middle to the foot; also the single large tooth at the anterior margin of the lorica. The 
anterior part of the lorica has about nine longitudinal folds, extending from the anterior margin to 
the constriction separating that part of the lorica covering the head from that covering the body. At 
the base of each of the two main toes are four minute substyles (fig. 21). 
Pond near Bangor, Me. (J. C. S., ’83). Turner (’92) records “liattulus tigris ” from the neighbor- 
hood of Cincinnati, Ohio, citing liattulus tigris of Hudson and Gosse and Diurella tigris of Herrick (’85) 
for accounts of the animal. Now, these two latter represent two entirely different auimals, Herrick’s 
animal being Ccelopus porcellus, while, as noted above, the Rattulus described by Gosse is not the real 
liattulus tigris. It is therefore impossible to say what the animal observed by Turner was. 
49. R. sulcatus Jennings. 
Not uncommon in shallow parts of Lake Erie about South Bass Island. 
Lake St. Clair (Jennings, ’94). Old Channel and West Twin Lake near Charlevoix, Mich. 
(Jennings, ’96). Sandusky Bay, Lake Erie (Kellicott, ’96). 
li. palpitatus Stokes (— Ccelopus bracliyurus Gossef). — Trenton, N. J. (Stokes, '96b). 
“ Diurella tigris Bory,” Herrick (’85) = Coelopus porcellus Gosse. 
Diurella insignis Herrick (’85). See Coelopus tenuior. 
CCELOPUS Gosse. 
As has been several times pointed out of late, this is a genus which was founded on an incorrect 
interpretation of the structure of the toes. When the Rattulid® are subjected to the revision which 
they so much need, probably the name Coelopus will disappear; until that is done it will be best to 
retain the names commonly used. 
50. C. porcellus Gosse. (Plate 18, figs. 22 and 23.) 
Not uncommon in the vegetation of shallow parts of Lake Erie about South Bass Island. 
Ohio and Minnesota (Herrick, ’85, under the name Diurella tigris Bory). Shiawassee River at 
Corunna, Mich. (Kellicott, ’88). Lake St. Clair, Crooked Lake, Newaygo County, Mich. ( Jennings, ’94). 
Old Channel, Charlevoix, Mich. (Jenuings, ’96). Sandusky Bay, Lake Erie (Kellicott, ’96). Waters 
connected with the Illinois River at Havana, 111. (Hempel, ’98). Pools, Hanover, N. H. (H. S. J.). 
51. C. bracliyurus Gosse. (Plate 18, fig. 24.) 
East Harbor, Lake Erie; swamp near fish-hatchery on South Bass Island. 
Shiawassee River at Corunna, Mich. (Kellicott, ’88). Pools, Hanover, N. H. (H. S. J.). 
C. tenuior Gosse. Doubtfully reported by Kellicott (’88) from the Shiawassee River at Corunna, 
Mich. Old Channel, Charlevoix, Mich. (Jennings ’96). Sandusky Bay, Lake Erie (Kellicott, ’96). 
Waters connected with the Illinois River at Havana, 111. (Hempel ’98). Diurella insignis Herrick (’85) 
apparently should he referred to this species. Weber (’98) refers it to Coelopus porcellus, yet an 
inspection of Herrick’s figure shows that the proportions are totally different from those of the latter 
species, while they agree fairly well with those of C. tenuior; moreover, Herrick had already described 
C. porcellus on the preceding page of his paper, under the name Diurella tigris. Diurella insignis ( C . 
tenuior) was found in Minnesota. 
Helerognatlius nolommata Schmarda (— Coelopus tenuior?). Brackish water near New Orleans 
(Schmarda, ’59), 
