496 THE ANATOMY OF LNVERTEBRATED ANIMALS. 



pores on the genital plates, through which their products are 

 extruded. Hoffmann has fcund the peritoneal fluid of the 

 males full of spermatozoa. 



Fig. 145.— Development of an Echlnid. (After Miiller.)— A, Echinopaedium of Fchi- 

 nvs pulchellus in the gastrula *taire. B, fully-developed Echinopaedium (Pluieus) 

 of the same species: a, mouth; 6, stomach and intestine; c. amis; A F, processes 

 of the hody into which prolongations of the internal skeleton extend. C, the 

 Echinopaedium of an Echinid in which the Echinoderm is so far advanced that 

 the spinas, pedicels, and pedicellarise are visible. D. Echiuopaedium of Echinus 

 liridus: a, mouth ; a', millet; b. stomach; b', intestine; c. rudimentary Echino- 

 derm; c', the ambulacra! sac; c", the external opening of its duct; A A, F F, B, 

 the processes of the body. 



In the Echinidea, as in the Ophiuridca, the Echinopae- 



