CNIDÄRIA 



117 



The Ephyra (Fig. 51, ii and 12, and Fig. 58), accordingly, 

 possesses a flat, discoid body, from the under-side of which 

 the manubrium hangs down. The margin is prolonged into 

 bifid inarginal lobes, each one of which bears a sensory body 

 between its alar lobes. Four of these are perradial, and 

 correspond to the radii of the oral cross, whereas the four 

 interradial ones fall in the radii of the gastral filaments. The 



Fig. 58. — Diagrammatic figure of an embryo of an Ephyra. o, cruciform mouth- 

 opening ; g/, gastral filaments; I, lobe-pouches ; /, alnr pouches; c, cathammata, 

 or regions of fusion of tlie peripheral intestine ; si;, sensory bodies. 



broad, flat gastral space is prolonged into sixteen peripheral 

 marginal pouches, which are connected by means of the 

 vascular plate. Of these pouches the eight perradial and 

 interradial ones are directly continuous with the lobe-pouches 

 and alar pouches. The ectoderm on the oral side of the disc 

 (sub-umbrella) forms a broad, band-like circular muscle, 

 while paired longitudinal muscle-bands sti-etch along the 

 marginal lobes and into the alar lobes. 



Hypogenetic Development of the Larvas of Pelagia. 

 — Schneider (No. 113) and Haeckel (No. 107) have already 



