45 G 



ARrilROPODA. 



feet are glands recalling iiepbridia in their history. It is possible that 

 these animals are to be placed among the Co3llielminthes. Maurohiotus* 



Pycn ogon Ida ( Pan topodu) . 



These marine animals have a cylindrical body, with a tubular probos- 

 cis in front and an abdominal appendage Ijehind, and four pairs of very 

 long legs. In front of tlie legs is a pair of small chelate appendages and 

 usually a pair more like pedipalpi. In the male there is an additional 

 jiaii- of ' ovigerous ' legs to which the eggs are attached after being 

 dejiosited by the female, thus giving a total of seven appendages, a nuui- 



FlG. 476. — N/jtnp]i<in i^tixryni, 



'■ ((jrii^.). r, clielioerif : 

 r, rostrum. 



ovigerous legs; p, pedipalpi ; 



bcr not reached in any arachnid. Diverticula of the stomach extend into 

 the legs ; a heart is present, but respiratory organs are lacking. The 

 Pycnogonids, which creep slowly over seaweeds and hydroids, may be il) 

 a distinct group of artliroproda, or (2) modified arachnids, or (3), and less 

 probable, Crustacea. Nijinpliou* PhoxicTiiUdiuDi* Colossendeis.* 



Class III. Malacopoda (Protracheata). 



These forms, inclfiding only a single family Pekipatid.?;, show 

 a strange mixture of annelid and arthropodan (or ' traeheate ') 



Fio. 477.— 7Vn'(OTh(,s i;i jinisis. (From Kalfour, after M 



cliaracters, so that they are usually regarded as representatives of 

 the stock, early separated from the annelids, fron: which the Insecta 

 luivo descended. They recall the annelids by the iireseuce of 

 lu^pliridia, so characteristic of that group, which begin by a closed 

 vesicle (reduced ctelom), pursue a short conrse, and expand into a 

 urinary bladder before o]iening at the bases of the legs (tig. 478, 

 .so). On the other hand they possess trachea', long nnbranched 



