ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
207 
•on the question of asymmetry, and on the resemblance between Cephalo- 
branchiate Annelids and Gasteropods. “ The initial asymmetry is no 
doubt due to an active cause like that which shows itself in Molluscs ; 
when once the tube is formed, it can accentuate itself by reason of the 
special conditions of existence it imposes on the animal.” 
New American Species of Megascolides.* * * § — Mr. F. Smith gives a 
brief description of Megascolides americanus sp. n., from Pullman, 
Washington. It is said to be very abundant, and to make burrows 
•sometimes over fifteen feet deep. It differs from its North American 
relatives in the presence of numerous small nophridia in each somite 
instead of two large ones, in the extent of the clitellum, and in several 
other characters. 
Regeneration of Fore-gut in Lumbriculus.f — Dr. F. von Wagner 
described this in 1893 as occurring without the help of the ectoderm. 
He finds, however, that an unmistakable invagination of ectoderm 
occurs. At the point where the endoderm of the gut is for a time in 
contact with the superficial ectoderm, forming a provisional mouth, a 
true stomodaBal insinking develops. 
Species of Acanthobdelia4 — Prof. Al. Kowalevski has studied the 
structure of Acantliobdella peledina Grube, found by Middendorf as 
a parasite on the fishes of the J enissei, and Acantliobdella Esmontii, found 
D 7 0. Grimm in the Caspian. The chief interest of the first species is 
its likeness to Cksetopods ; it may be considered as a transitional form. 
1 1 has setae and a body-cavity. The second species is much more like 
Ncphelis. 
Rotatoria. 
New Species of Rotifers from the Illinois River. § — Mr. Adolph 
Hcmpel gives a short description, with figures, of three new species of 
Brachionus : — B. variabilis, B. mollis , and B. punctatus. The first is 
rather a bad name, since all Rotifers vary, and none more so than the 
different species of Brachionus. B. mollis is peculiar in having a very 
thin soft glassy transparent lorica, with no spines at all, either anteri- 
orly or posteriorly. B. punctatus has, since its discovery in America, 
been found near London by members of the Quekett Club, and also in 
Russia by Mr. A. S. Scorikow. 
Trochosphaera solstitialis.il — Dr. C. A. Kofoid reports the finding 
in the Illinois River and adjacent swamps of this rare and peculiar 
rotifer, first discovered by Surgeon Y. Gunson Thorpe, R.N., in China, 
.and described in this Journal in 1893 (p. 147). 
Rotifera of Sandusky Bay.^T — Dr. D. S. Kellicott gives a prelimi- 
nary list of rotifers observed at the lake laboratory provided for him by 
the Trustees of the Ohio State University on Lake Erie. Sixty-seven 
species are enumerated, with notes of their occurrence. One species, 
Melicerta flocculosa , is described as new, but no figure is given, which is 
■always a great drawback to future identification. 
* Amer. Nat., xxxi. (1897) pp. 202-4. 
t Zool. Anzeig., xx. (1897) pp. 69-70 (1 pi.). 
+ Bull. Acad. Sci. St. Petersbourg, v. (1S9G) pp. 1-4. 
§ Bull. Illinois State Laboratory Nat. Hist., iv. 1896. 
il Science, iv., Dec. 1896, pp. 985-6. 
1 Proc. Amer. Micr. See., 1896, pp. 155-64. 
