232 



GASTROTRICHA 



CHAP. 



in America and 0. Zelinka x in Germany have contributed, the 

 former a careful description of a number of new species and their 

 habits, the latter a complete monograph of everything that is 

 known of the Order. 



The Gastrotricha dwell among filamentous Algae and organic 

 debris, and are of frequent occurrence with Protozoa and Eotifera 

 of similar habit. The largest known measures only 400 /* ( 

 in.) in length, and the smallest run as low as 74 fi ( 3 ft in.). 



Fig. 119. Gastrotricha. (From Zelinka.) A, Chaetonotus bogdanovii, side view (after 

 Schimke witch) ; B, Gossea antenniger (alter Gosse) ; C, Dasydetes goniathrix (after 

 Gosse) ; D, Dasydetes saltitans (after Stokes) ; E, D. longisetosum (after Metsclmi- 

 koff) ; F, Chaetonotus spinulosus (after Stokes) ; G, Chaetonotus schultzei (after Gosse 

 and Butschli). (Magnified.) B-F, x about 390 ; G, x about 125. 



We shall follow Zelinka in his description of the common 

 species Chaetonotus larus as a type. The body is nearly circular 

 in section, flattened a little on the ventral side. The apertures 

 are the terminal mouth ; the anus, nearly terminal and slightly 

 dorsal ; the two kidney openings, ventral, nearly half- way down 

 the trunk ; besides the pore of a cement-gland on either terminal 

 process. The short ventral and post-anal portion of the trunk 

 with its processes therefore corresponds to the foot of a Eotifer. 

 The integument of the body is a thin nucleated hypoderm, not 



1 Zcitschr. wiss. Zool. xlix. 1890, p. 209. 



