Dr. M. Schiiltze on the Terrestrial Planarise. 9 



statements are founded merely upon a confusion between the 

 anterior and posterior extremities, which may be excusable, as 

 Blanchard did not see the animal living *. With such a notion, 

 however, Blanchard's statements upon the central nervous system 

 in Polycladus Gayi of course lose all value. This is said to 

 consist of two cerebral ganglia, situated over the seminal vesicle, 

 and two cords running backwards (forwards) which are again 

 interrupted by several (up to 14) small ganglia. What organ 

 has been confounded here with the nervous system, it is hard 

 to say ; at any rate no cerebral ganglia can be situated above 

 the seminal vesicle, but they must be sought at the opposite 

 end of the body. 



In this certainly imperfect state of our knowledge of the struc- 

 ture of the terrestrial Planarice, I very opportunely obtained a 

 specimen of such an animal. It was found by Dr. Burmeister, 

 near Rio Janeiro, and put, whilst living, into spirits, in which it 

 had been very well preserved, with the exception of an accidental 

 injury in the middle of the body. The tissues, indeed, were 

 only partially applicable to microscopic examination. Never- 

 theless, by the aid of glycerine, which is often exceedingly 

 serviceable in the clearing up of spirit preparations for the 

 microscope, I succeeded in obtaining an insight into the finer 

 structure of several systems of organs. Unfortunately, the 

 development of the generative organs was so backward in the 

 animal, that nothing could be ascertained with regard to the 

 sexual glands. 



My specimen belongs to none of the 26 species above cha- 

 racterized, and I therefore introduce it into the system under 

 the name of Geoplana Burmeisteri. Its length is 2|- inches; 

 its greatest breadth behind the middle of the body ^ an inch ; 

 its thickness 1 line. The body is pointed before and behind ; 

 attenuated more rapidly posteriorly, and anteriorly very gra- 

 dually and drawn out into a long point. The colour of the 

 back is sepia-brown, blackish-brown at the anterior extremity; 

 a pale brown streak runs along the middle of the back from the 

 anterior to the posterior extremity, very distinctly and sharply 

 bounded by nearly black margins in the anterior quarter 

 of the animal, then obsolete, and only distinct again in the 

 vicinity of the hinder extremity. On the back also a quan- 



* I may, however, mention in passing, that this is not the first error of 

 the kind into which this observer has fallen. He has slipped into the 

 same mistake with the Caryophyllceus, which is so common in the intestine 

 of Cyprinus Brama (Ann. des Sci. Nat. 3 ser. x. p. 323, pi. 12. figs. 1, 2). 

 Here also the extremity furnished with the organs of generation is marked 

 as the anterior, whilst it is really the posteriory as was rightly perceived 

 by all the older observers. 



