394 



ESCHARID^. 



tive character. There is no trace of the partially closed, 

 loop-like marginal fissure which occurs in several o£ the 

 members of the genus. The large avicularium with a 

 hooked beak is altogether wanting; but the small oval 

 avicularia are generally distributed in great numbers over 

 the zoarium. 



The semielliptical shape of the aperture is concealed by 

 the rostrum and the growth of the peristome; but it is 

 apparent in the marginal cells. The adherent base is a 

 shining subgranular crust, divided by well-marked lines 

 into somewhat ovate cell-areas ; these are destitute of an 

 oral aperture ; but its place is usually occupied by a small 

 circular avicularium. 



The Lepralia lohata of Busk is founded on the rudi- 

 mentary stage of a Retepora (possibly of the present 

 species) ; and the mode of growth is well displayed in one 

 of the figures which he has given in his ' Crag Polyzoa ' 

 (plate xxii. fig. 4 «) . In the centre of a spreading crust 

 a rather thick subcircular patch is formed ; and round the 

 edge of it rise a number of short erect lobes, which con- 

 stitute the rudiments of the reticulated cup. As they 

 increase in height they anastomose and form the first 

 meshes of the network. 



Fig. 18. 



Young stale of Kctcjxira. 



