344 ZOOLOGY. 



character of the axis or internal arm- skeleton." In fine, the charac- 

 teristics of the new type are such as to isolate it, at least with family 

 value, from all the other Ophiuroids, and this is established under the 

 name " AstrophiuridcCj'^^ by Mr. Sladen, with the following character- 

 istics : 



The arms, with an Ophiuroid disk, included in a pentagonal body ; 

 the teeth absent ; the armature of the mouth simple and imperfect ; the 

 pores for the ambulacral feet separated by narrow septa, which are per- 

 pendicular to the rays j the interbrachial cavity very broad. 



WOEMS AND WOEM-LIKE ANIMALS. 



MODrFICATIONS OF WOEM-TYPE. 



The arrangement of worm-like animals in the systema naturae has taxed 

 the learning and ingenuity of naturalists to a high degree, and especially 

 during the last quarter of a century. Within the last two years sev- 

 eral attempts have been submitted, exhibiting the widest diversities from 

 each other. Whatever may be the ultimate verdict, it is quite certain 

 that there is no concurrence now as to the value of the characters used 

 to distinguish the various groups. As an indication of some of the tend- 

 encies in the taxonomy of the types in question, several of the sys- 

 tematic expositions are noteworthy. 



Mr. A. Giard, in connection with a communication on the Orthonectids, 

 gives his ijecnliar views of the worm-like animals.* 



The name Vermes is accepted as the designation of a "sub-kingdom" 

 which includes Orthonectids, Dicyemida, Trematoda, Cestoda, and Tur- 

 bellaria. 



The name GYMNOTOCAis suggested for the "Annelida and associated 

 groups," as well as the Bryozoa, and also the true Mollusca. (The 

 Tunicata, he thinks, "must be i)laced at the foot of the sub-kingdom 

 Vertebrata.") 



The designation Nematelmia is used for the Nematoida, Echinorhyn- 

 cha, Desmoscolecida, Gastrotricha, &c. 



THE intestinal WORMS OF THE HORSE OF DENMARK. 



Dr. H. Krabbe has investigated the relative frequency of occurrence 

 of different entozoa of the intestinal canal of the horse in Denmark.! 

 The following is the ratio to the hundred for the different species ascer- 

 tained, which are six in number, namely : 



Times. 

 Twnia perfoUata 28 



" mamillana 8 



* Giard (A.). The Orthonectida, a new class of the Phylum of the Worms. Quart 

 Jour. Mier. Sci., vol. xx., pp. 225-240. 



t Krabbe (H.). Researches on the occurrence of Intestinal Worms in the intestinal 

 canal of the Horse. Ann. Mag. Nat. Hist., (5,) vol. vi, pp. 96,97. 



