MARINE INVERTEBEATA OF GRAND MANAN. 11 



might also be considered, as bearing on this question, that the medusaB of Tubularia 

 never become free, as in the Gorynidai. 



It follows, also, from the above, that the species just described, having basal tenta- 

 cula, is inferior to Coryne and its allies, in which they never appear, so that it is 

 correctly classed between that genus and Tubularia; and if, as is probable, the single 

 circle of tentacula in the Sertulariadce is homologous with the basal tentacula of 

 Acaulis and Tubularia, it would follow that that family should stand lowest in the 

 scale. Thus, as will be seen in the arrangement of the hydroids in this paper, it 

 is a reversal only of the series followed in Johnston's work which is proposed, 

 without derangement of the grouping of the families. 



Hydractinia echinata, Johnst. Alcyonium ecliinatum, Auct., Gould, Inv. Mass. 



Clava multicornis, Johnst. Coryne squamata, Miill., etc. 



Under these two names are probably included the polype forms of several species 

 of our North Atlantic naked-eyed medusae. 



PROLES MEDUSIN^. 



Among the very numerous species of medusse observed in this region, the 

 following only were identified. The notices I prepared of new species, owing to 

 the circumstances under which they were observed, are too short for publication. 



Sarsia mirabilis, Agass., Mem. Am. Acad., 2d ser. iii. 224, pi. iv. 



HippoCRENE suPEECiLiARis, Agass., 1. c, 250, pi. i. 



Staurophora laciniata, Agass., 1. c, 300, pi. vii. 



AuRELiA AURiTA, Miill,, Gould, Inv. Mass. 



Cyanea Postelsii, Gould., Inv. Mass. A Strobila of large size, probably the 

 polype form of this Cyanea, was taken in various stages of development, in 30 

 fathoms, on the Hake Ground. It was of a light salmon color, with very long 

 superior tentacula, which it used in walking inverted on the bottom of the sea. 



BEROID MEDUS/E. 



Pleurobrachia rhododactyla, Agass., 1. c, 313, Part ii., pi. i. 

 BoLiNA ALATA, Agass., 1. c, 349, Part ii., pi: vi. 



