PETEES' HANDBOOK OF ZOOLOGY. 37 



his Vermes and Arthropoda, In liis general view of tlie members 

 of tlae group, however, he agrees pretty closely with Vogt, except 

 that he excludes the Eotatoria and Gregarinae and includes Sagitta. 



The Vermes, according to Dr. Carus, form five classes — naAely, 

 Annulata, Grephyrea, ChaBtogrfatha, Nematelminthes, and Platyel- 

 minthes. With regard to the first of these groups we need only say 

 that the author closely follows Grube in his classificatiou, and that he 

 has given a most careful analysis of the families and genera of the 

 [Ringed-worms. Here and there we find new family groups defined, 

 and on p. 447 Dr. Carus proposes a new provisional section, Halo- 

 scolecina, with two families for the reception of the problematical 

 genera Dero and CapiteUa and their allies. 



The Gephyrea {Sipunculus and its allies) placed by many authors 

 with the Holothuroidea among the Echinodermata form the second 

 class of the Vermes in the system of Dr. Carus, who gives as his 

 reason for referring them to this position that " although their 

 organisation is not exhaustively known, the deficiency of calcifica- 

 tion in the skin, the absence of the aquiferous system with its 

 dilatable appendages, the decided bilateral symmetry, the bristles and 

 other characters indicate their proper position to be amongst the 

 "Worms." — (p. 452.) At the same time these curious creatures 

 present many characters incompatible with their occupying a place 

 even among the multifarious types of the Annelides, and perhaps the 

 best course that can be adopted at present, is that followed by our 

 author, of placing them in a distinct (provisional) group in the 

 immediate vicinity of the Hinged- worms. Dr. Carus divides them 

 into four families — namely, the Sternaspidea, Echiuridea, Sipunculidea 

 and Priapulidea. 



The SagittcB, which have the somewhat questionable honour of 

 having been referred by diflerent writers to no less than three of the 

 great primary divisions of the animal kingdom, constitute Dr. Cams' 

 third class of Vermes, the Chsetognatha, It is hardly fair of the 

 author, however, to ascribe to the late Edward Forbes the establish- 

 ment of the Molluscous order Nucleobranchiata for the reception of 

 these puzzling creatures, considering that that group was founded 

 many years ago by De Blainville for the genera Carinaria and Firola, 

 and that those Zoologists who referred Sagitta to such a position were 

 led to do so by a very laudable desire to avoid establishiug a new group 

 for animals of which they knew next to nothing. In the present day 

 Zoologists are, as stated by Dr. Carus, pretty well agreed that the 



