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ELLIOTT SOCIETY. 



131 



concentric canals. The ocellus is always placed in the trans- 

 parent tissue which surrounds the darker mass of this bulb, and 

 is therefore always marginal, not tentacular in its position. 



The different genera included under this head differ widely in 

 the form of the tentaculum which in Sarsia proper is long, very con- 

 tractile, and lash-like, while in Dipurena and Corynitis it is short 

 and clavate. Prof. Forbes' genus, Slabberia, also, is the only genus 

 in the whole group of Endostomata, which appears to have the sex- 

 ual organs entirely on the radiate tubes. With deference to that la- 

 mented and able observer, I must entertain a doubt as to the exact- 

 ness of this observation for the present. In this group, also, 

 occurs the only instance of which I know, in which the digestive 

 cavity appears to be divided into two distinct stomachs. I refer 

 to a new genus, Dipurena, described below. 



CORYNITIS, nov. gen. 



General form conico-campanulate. Bell-wall of great thick- 

 ness above. External surface ornamented with scattered groups 

 of small thread-cells, each enclosed in a containing cell. Di- 

 gestive trunk massive — sexual organs confined to the upper por- 

 tion. Between the four radiate tubes, the bell cavity rises in four 

 over-arched spaces of unusual height. The four ocellated mar- 

 ginal bulbs of the short tentacula arising from them have the same 

 massive character as the digestive trunk. The tentacula are 

 clavate and bristle with large pads of thread-cells. A sinus occu- 

 pies the interior of the ocellary bulb, and is connected by canal 

 through the axis of the tentacular shaft with another and larger 

 sinus occupying the interior of the enlarged extremity of the ten- 

 taculum. The inter-communicating canal may be completely 

 obliterated by the contraction and closing together of its walls, 

 and though this appears to be done at will in the younger stages 

 of growth, I have not been able satisfactorily to ascertain that it 

 was not a permanent condition in the full-grown adults. 



The larva is a coryne with a short thick polyp and few tenta- 

 cula. The medusa-buds grow in the usual position, just below or 

 among the lower tentacula, and the peculiar character of the ten- 

 taculiferous bell-margin is conspicuous at an early age, PI. 9, 

 ff. 6, 7, 8, a. Two of the tentacula are developed a considerable 

 time before the others. They at first appear as hollow enlarge- 

 ments of the margin at opposite poles of one of the diameters of 

 the marginal circle, They increase in size and gradually project 



