49 

 Icv/rr rcle. Thus the e^,^, ir. divided reridionally into t;o 

 colic of arproxinatoly oGual size, When the division is com- 

 plete '.he blastomeres do not remain in close union, but 

 rove ar)art so that the tv.-o spheres are connected by only 

 sr^all arcs of their cirourr.ference. The nrotcrlas-^ic bridge, 

 v;hich frecuently occurs in hydroid egf^s at the lower pole 

 .iust previous to the ccpletion of the tv/o-cnlled stage, 

 is usually to be seen in the egg of this species; but, i^ is 

 much less conspicuous than is the case in Sto-Totoca. And 

 viher it occurs is less definite and clearly defined than is 

 the condition i'_Hydractiriia, as described and figured by 

 Bunting. Metschnikoff also figures a very beautiful ex- 

 ample of this prcto-las~ic ccni^ectio" in the egg of fausi,- 

 thoe marginata. In Turrito_;;^sis thepondition is nuch lilce 

 that of Rathkea fasciculata, as sh-v^n by the last -entioned 

 observer, in v/hich the con'^ections instead of becoming a 

 very definite bridge re-ain for a tine as a less clearly 

 outlined portion of the ectosarcal naterial. Proto- las-iic 



