470 Mr. E. T. Browne on the Medusm 



Maas have also expressed their disapproval of Hseckel's 

 Staurostoma. 



The most interesting character of Stauropliora is the posi- 

 tion of the stomach, month, and the gonads. How thej 

 olDtained their present position will be more readily nnderstood 

 after considering the position of these organs in Laodice. It 

 appears to me that Stauropliora is descended from a Laodice- 

 like mednsa. 



In Laodice jmlclira the radial canals are extremely large 

 and the gonads are situated upon them. The gonads are 

 arranged in a series of short folds forming a row on each 

 side of the canals, close to the subumbrella. They extend 

 along the whole length of the enlarged canals right up to 

 the central stomach, where they very nearly meet the gonads 

 belonging to the adjacent canals. In my original description 

 of Laodice pulchra the enlarged portions of the radial canals 

 were regarded as lobes of the stomach, and not as radial 

 canals. I considered the very short canals between the lobes 

 and the circular canal to be the true radial canals. This 

 species certainly has the appearance of possessing a very 

 large four-rayed stomach with gonads extending along the 

 lobes and a large central mouth with the margin in folds. 



If one were to slit open along the middle the enlarged 

 portions of each radial canal of Laodice j)ulcJira, and imagine 

 the cut margins to be the margins of a mouth, then the 

 position of the mouth, stomach, and gonads would be similar 

 to those of Staurophora. 



I think the mouth of Staurophora has arisen by the out- 

 growth of a central mouth along the enlarged portions of the 

 radial canals of a Laodice-\\\s.Q medusa, and consequently 

 those portions of the radial canals have been converted into 

 a four-rayed stomach. The gonads have not changed their 

 position, but in Staurophora they have lengthened slightly 

 and meet in the centre of the cross. 



The earliest stages of Staurophora laciniata are very similar 

 to those of a young Laodice. They have a small central 

 stomach and mouth and four radial canals. A. Agassiz has 

 traced the development of the mouth of S. laciniata, and his 

 figures clearly show how the mouth grows out to form a 

 perradial cross. 



There is no disputing the fact that in Staurophora the 

 gonads are upon the walls of the stomach and occupy the 

 position of the gonads of an Anthomedusa. There is, how- 

 ever, very good evidence that Laodice imdulata comes from 

 a calyptoblastic hydroid belonging to the genus Cuspidella, 

 and there are also Laodiceidae with gonads on the radial 



