178 MR. H. CHARLTON BASTIAN'S MONOGRAPH 
7. U. INFREQUENS, Carter. 
Loc. cit. p. 43, pl. iii. fig. 30. 
* Female, the same as the foregoing species, but a little larger in every way." 
* Alimentary canal and organs of generation the same generally. Ova unde 
segmentation; and the embryo developed in the ovisac, but not liberated there," 
“ Ocelli, the same in situation, but semi-opake and of a yellowish colour throughout,” 
** Size, undetermined.” 
“Male. Same as the female, but with a short curved tail, presenting on each side of 
the inner curvature a membranous expansion supported on setaceous ribs, which extends 
from the tip of the tail to some little distance above the anus. Organs of generation the 
same as in the foregoing species; form of testis undetermined.” 
* Hab. The same as last." 
Note appended on June 17, 1865.—Whilst this memoir has been going through the 
press, I have completely satisfied myself of the general correctness of Schneider's views 
. (Reich. and Du Bois-Reym. Archiv, 1863) regarding the nature and arrangement of the 
nervous system in Ascaris megalocephala; and in another memoir, laid before the Royal 
Society of London on the 15th of this month (“On the Anatomy and Physiology of the 
Nematoids, Parasitic and Free; with observations on their Zoological Position and 
Affinities to the Echinoderms”), I have described and figured this system as it exists in 
A. lumbricoides, A. osculata, and A. marginata. The arrangement which has now been 
recognized in these and other species, either by Schneider or myself, will, I believe, 
prove to be the typical condition of the nervous system in the Nematoids generally, 
although the difficulty of actually demonstrating it is often extreme. I am still of 
opinion, however, that the so-called « cesophageal ring" met with occasionally in both 
free and parasitic species is not to be considered a portion of the nervous system of these 
animals. Reasons for this belief, as well as many new facts and views concerning the 
anatomy of this interesting group of animals, are contained in my last memoir above 
mentioned. 
ERRATA. 
Page 73, ' omitted before first footnote. 
78, note, line 12, instead of par read pas. 
82, line 22, instead of (Schwanzdriisefi) read (Sehwanzdrüsen). 
82, line 31, instead of Tylelenchus read Tylenchus ; and the same in pp. 83 (twice), 84 (twice), 85, 8) 
94, 96 (four times), 110, 113. | 
93, instead of 7. TRIPULA read 7. TRIPYLA. 
94, instead of * 21, Lixgouourvs read * 21. Linnomœus. 
148, line 27, instead of 166 read 167. 
165, line 15, instead of SPILIPHERA read SPILOPHORA. 
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