THE HAIR-WORMS. 



171 



The second suborder, Gnrdiacca or hair-worms, differ in 

 their mode of development from the true Nematode Avorms, 

 the embryo of Gordius being armed with oval spines, thus 



Fig. \l9.-Gorilins aquations. A, cg2 ; B, eg:."; undergoing segmentation of the 

 yolk ; C, embryo (gastrula) with the i>rimitivc stomach, an infold of the outer ger- 

 minal layer of cells (ectoderm); D. embryo farther advanced ; E, larva, with the 

 three circles of spines retracted within the oesophagus; F, the same stage greatly 

 enlarged to show the internal organs ; c, middle circle of spines, the head being 

 retracted; m, muscular layei (?) ; t, beak or proboscis; z, intestine ; z, z, embryonal 

 cells; /, excretory tube leading from t/, the secretory glands; ce, oesophagus ; .', rec- 

 tum; 11, anus. G. the second larva, encysted 111 a fish (after Villot). H, GorditlS 

 cm hit, end of body of male, much enlarged. I, (iordinx aifUCtlicus, end of body 

 ol male, much enlarged. K, (lordms aqtlditcus, natural size.- (.11, I, K, drawn from 

 nature by J. S. Kingsley.) 



reminding us in this respect of EchmorJiynch-i, but the em- 

 bryos, larvie and adult have a well-developed alimentary 

 canal. 



