NOTES ON THE MORPHOLOGY AND DEVELOP 

 MENT OF TWO SPECIES OF EUDENDRIUM. 1 



EDGAR DAVIDSON CONGDON, A.M. 



The observations presented here were made while describing 

 and cataloguing hydroids collected at Bermuda during the sum- 

 mer of 1903. They have to do with two species of the genus 

 Eudcndrinm. In one of these, E. ramosum, the development of 

 the female gonophore is outlined, since no such account, so far 

 as I am aware, has yet been given for any member of the genus. 

 To a review of the histological conditions found in E. liargitti is 

 added a description of its oogenesis which is unique for the genus 

 in that the egg grows by the bodily absorption of entoderm cells. 

 Endoidrinni liargitti is here described for the first time. 



To those who are acquainted with the contributions of Pro- 

 fessor Charles W. Hargitt to our knowledge of the genus, the 

 significance of the specific name will be evident. I wish to 

 acknowledge my personal obligation to Professor Hargitt for 

 suggestions and criticisms relating to my work. 



DEVELOPMENT OF THE FEMALE GONOPHORE OF EUDENDRIUM 



RAMOSUM. 



The egg cells destined for the female gonophore here, as in all 

 members of this genus, have their origin in the unfascicled 

 branches of the mature colony and pass distally to the region 

 where the future gonophore is to develop. They are first dis- 

 tinguished from epithelial cells by their deeply staining cytoplasm 

 and large nuclei. They are found scattered along through the 

 entoderm of the branches and pedicels and are most abundant 

 close to hydranths bearing young gonophores. They also may 

 be seen in the entoderm of hydranths which as yet show no 

 external signs of gonophores. 



Conditions point clearly to their migration up the branches. 

 They show an increase in size proportional to their proximity to 



1 Contributions from the Zoological Laboratory of Syracuse University. 



27 



