8 Prof. AUinan on the Hydroida. 



regard as the same bodies in a more advanced stage, were also 

 found attached to the sides of the jar. They consisted of a white 

 tubular filament, about 4 lines in length, attached to the glass 

 by one extremity, and developed at the opposite into a minute 

 polype having a general resemblance to the polype of Corymorpha, 

 but with only six or eight tentacles composing the posterior 

 verticil, while the anterior tentacles were about the same in 

 number, thicker and shorter than the posterior, with blunt, 

 almost capitate extremities, and, like the posterior tentacula, 

 disposed in a single verticil. 



Other still more advanced stages were also found attached to 

 the sides of the jar. They had attained to about double the size 

 of the last, had the posterior tentacles composed of a verticil of 

 sixteen or twenty, while the anterior tentacles, though still dis- 

 posed in a single verticil, had become multiplied to about the 

 same extent. 



Beyond these three stages I was unable to trace the develop- 

 ment through any further steps; the last of them, however, 

 manifestly requires little to convert it into the form of the adult 

 Corymorpha. 



If it were not that the medusoids thrown off from the adult 

 polype in my jars had, so far as I could find, all perished before 

 the formation in them of generative elements, I should have 

 regarded the little organisms just described as presenting thi'ee 

 stages in the development of the embryo from the ovum. In 

 the absence, however, of all evidence of the presence of ova, I 

 believe it will be safer to view them as difl'erent stages in the 

 development of a gemmule liberated, in some way unknown, 

 from the adult specimens in the jar. 



II. Diagnoses of new Species of Tubularidse obtained, during the 

 Autumn of 1862, on the Coasts of Shetland and Devonshire. 



Clava diffusa, mihi. 



Polypes about \ inch in height, light rose-colour, developed 

 at intervals upon a creeping reticulated stolon ; tentacula about 

 twenty. 



Gonophores scattered, commencing just behind the posterior 

 tentacula, and thence extending singly or in small clusters for 

 some distance backwards upon the body of the polype. 



In rock-pools at low- water spring-tides. Out Skerries, Shet- 

 land Isles. 



The present species differs from all other described species of 

 Clava in the gonophores being scattered and extending for some 

 distance backwards, instead of being aggregated in closely ap- 

 proximated clusters immediately behind the posterior tentacula. 



