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Show 738 DR. T. s. COBBOLD ON N E W OR RARE ENTOZOA. [NOV. 18, beyond 3 feet. I believe this entozoon was first described anatomically by Prof. Owen, from the College specimens above mentioned ; but the only original remarks on the subject that I have seen from his pen are some few contained in the article "' Entozoa" in Dr. Todd's ** Cyclopaedia of Anatomy,' and others given in his 1 Lectures on Comparative Anatomy.' From the published dates of these contributions (1839 and 1843 respectively), I am led to conclude that the first discovery of this worm actually rests with Mr. Darwin, since the late M . Diesing's specific description and nomenclature was evidently based on an examination of specimens obtained by Natterer in Brazil, the date of which would probably be about 1833, or perhaps a year later. However, as Natterer was many years previously resident in Brazil, and no special date of his particular " find " is given by Diesing, it is impossible for me to speak with certainty on this point. It is perhaps of little moment; and under any circumstances the systematist's specific title must be allowed to stand. M y examination of the females confirms Prof. Owen's statement respecting the simple character of the uterine organ and the forward position of the reproductive outlet. To be precise, I find that the vulva is placed -^V m c h below the points of the labial papillae. Of these papilla? 1 think there are ten or twelve, two of which project conspicuously beyond the rest, forming, as Diesing well observed, conical spines. Their length from base to apex is scarcely more than yi-ff inch; but their appearance suggests a structural affinity with the similar oral spines occurring in the Guinea-worm. In Dracunculus, however, according to Bastian, the two large spines are placed before and behind the mouth, not laterally. This parasite from the Ostrich does not reproduce viviparously; at least there were no free embryos in the uterine duct. The eggs were chiefly of two sizes, those in which yolk-segmentation was going on measuring y^0 inch in length, whilst the perfectly mature ova, containing coiled embryos, gave an average of -^J*-^ inch, being at the same time proportionally broader than the smaller eggs, whose transverse diameter was not more than yinnr h~'ch. As this worm has probably never been figured, I append a representation of the male (Plate LXIV. fig. 1), also an outline of the head and tail of the female (fig. 2), of the natural size, with a separate outline of the oral spines of the latter magnified sixty diameters (fig. 3). I likewise represent the egg in two stages of growth (fig. 4). Lastly, I may remark that this worm has not hitherto been recorded from the cavity of the stomach. That on this particular point there is no error in Mr. Darwin's MS., I think highly probable, not only from the distinguished collector's known accuracy, but from the circumstance that the parasites were so much coiled round one another that it took me nearly half an hour to unravel and separate them. I further presume that the tangled state was the condition in which they were originally found in the bird's stomach. 2. FILARIA IMMITIS, Leidy. During the autumn of 1869 I received from Mr. Swinhoe the heart |