REPORT ON ZOOLOGY. 229 



Dfders, which he calls Intestinaux Cavitaires and Intest. Paren- 

 chymateux, the former answering to the Nematoidea of Rudol- 

 phi, the latter comprising the last four orders of this author. 

 Cuvier admits, however, that there is a great difference in the 

 respective organizations of these two groups. In fact, the Ne- 

 matoidea, raised so much above the other Entozoa by their di- 

 stinct nervous system, are now generally allowed to approach 

 closely the Annvdose structure, if not to belong to that division 

 of the animal kingdom. Mr. MacLeay long since referred them 

 to that type, observing, that in a natural arrangement it seems 

 hardly possible to separate them far from Lumhricus and Gor- 

 dius*. With Blainville they also form a portion of his Entn- 

 mozoaires Apodes\. In a more recent publication J this last 

 author has gone further into detail with respect to the arrange- 

 ment of the Entozoa in general. He thinks they constitute 

 two classes at least ; the greater portion forming the last class 

 in his type Entomozoaires (in which class he includes the Ui- 

 rudinidce) ; the remainder (comprising the third and fourth 

 families of Cuvier's Intest. Pareiichymateiix) forming a sub- 

 tjrpe intermediate to the Entomozoaires and Actinozoaires (or 

 Zoophytes), though on the whole approaching nearest to the 

 former. Blainville does not admit that in the classification of 

 the Entozoa M'e should be at all more influenced by their pecu- 

 liar habitat than in that of other animals. He looks only to the 

 organization, which leads him to place in the same order ( Oxy - 

 c4phaUs, Blain.) Filaria, Gordius, and Vibrio, genera certainly 

 not very dissimilar in structure, though residing in very differ- 

 ent situations. His other orders in the class Entomozoaires 

 Apodes include in like manner both external and internal worms. 

 There can be no doubt that this principle is just to a certain 

 extent. Indeed it is supported by the opinions and researches 

 of others. Lamarck and Bory-St.-Vincent both suspected an 

 affinity between the Vibriones and the true Vermes. Duges, in 

 the Ann. des Sci. for 1826§, has instituted a close comparison 

 between the Vibriones and the Oxyures of Rudolphi, and from 

 an examination of their digestive and reproductive systems, 

 seems decidedly to think that they belong to the same group. 

 Professor Baer of Konigsberg, whose researches have tended 

 greatly to elucidate the structure and affinities of the Entozoa, 

 has in a memoir (or rather one of a series of memoirs) on the 

 lower animals, published in the 13th volume of the Nov. Act. 

 Sfc. Nat. Cur., endeavoured to show that neither the jK?2^osoa nor 



* Hor. Ent., p. 224. f Principes d'jinat. Comp., tab. 7. 



\ Art. Vers in the 57th vohime of the Dic^ des Sci. Nat, published in 1828. 

 This treatise also appeared separately under the title of Manuel d'Helmin' 

 tholo(jie. § torn. ix. p. 225. 



