178 MR. H. CHARLTON BASTIAN'S MONOGRAPH 



7. U. INFREQUENS, Carter. 



Loc. cit. p. 43, pi. 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 undergomg 

 segmentation ; and the embryo developed in the ovisac, but not liberated there." 



" Ocelli, the same in situation, but semi-opake and of a yellowish colovu' throughout." 



" Size, undetermined." 



" Male. Same as the female, but with a short curved taU, 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." 



" JSab. The same as last." 



Note appended on Jtme 17, 1865. — Whilst this memou- has been going through the 

 press, I have completely satisfied myself of the general correctness of Schneider's views 

 (Reich, and Du Bois-Eeym. Archiv, 1863) regarding the nature and arrangement of the 

 nervous system in Ascaris megaloce])hala ; and in another memoir, laid before the Eoyal 

 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. Imibricoides, A. osculata, and A. marglnata. 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 diificulty of actually demonstrating it is often extreme. I am still of 

 opinion, however, that the so-called " oesophageal 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 1 2, instead of par read pas. 



„ 82, line 22, instead q/"(Schwanzdriisefi) read (Sebwanzdriisen). 

 „ 82, line 31, instead of Tylelenchus read Tylenchus ; and tbe same in pp. 83 (twice), 84 (twice), 85, 89, 



94, 96 (four times), HO, 113. 

 ,, 93, instead of 7. Tripula read 7. Tripyla. 

 „ 94, instead of " 21. Linhomomius read " 21. Linhomceus. 



„ 148, bne 27, instead of 166 read 167. 



„ 165, line 15, tns^eac/ o/'Spiliphera read Spilophor.v. 



) 



