314 Mr. Forbes and Mr. Goodsir on Corymorpha nutans. 



bottom in the Bay of Stromness, Orkney. When placed in 

 a vessel of sea-water, it presented the appearance of a beau- 

 tiful flower. Its head gracefully nodded (whence the appro- 

 priate specific appellation given it by Sars,) bending the 

 upper part of its stem. It waved its long tentacula to and 

 fro at pleasure, but seemed to have no power of contracting 

 them. It could not be regarded as by any means an apa- 

 thetic animal, and its beauty excited the admiration of all 

 who saw it. 



The following is the generic character given by Sars. 



Gen. Corymorpha, nov. Corpus longum, cylindricum, moUe, 

 superne clavato-vesiculosum, infeme conico-attenuatum, tubule cu- 

 taceo hyaline tenuissime partem corporis inferiorem circumdante, 

 libere (nen affixum) insidens. Clava cenica, basi serie tentaculerum 

 longorum circumdata, et ostentaculis brevibus sparsis. 



1. Spec. Corymorpha nutans. Cerpere hyaline, lineis longi- 

 tudinalibus pallide rubris. 



The affinities of this genus may be stated thus : The family 

 of Tubulariadce is a group of Hydroid polypes connecting 

 the true HydrcB with the Sertulariadce, This connexion is 

 twofold, — 1st, between truly naked polypes and such as form 

 a horny case ; and 2nd, between polypes mostly simple or 

 individual in their nature, and polypes truly compound. It 

 is not too much then to expect, that the characters essentially 

 generic in this family, should depend on this double pro- 

 gression from one alliance to another, as well as on some 

 characteristic point in the organization of the animals com- 

 prising the group, considered as members of one family ; in 

 other words, on one positive and two comparative subjects of 

 character. 



The comparative characters we find, — 1st, in the presence, 

 absence, or nature of a tube, indicating a progression from 

 the Hydr(B ; and 2n J, in the form of the tube when present, 

 whether simple or branched, indicating an approach to the 

 Sertulariadce, 



The positive character we see in the arrangement of the 

 tentacula surrounding the head, which arrangement is truly 

 generic among the Tubulariadce, and not merely a family 

 character as in the preceding and succeeding families. Con- 



