224 Natural History Bulletin. 



not inserted on the front of the stem. The other Sertiilariu 

 is a beautifullv ornamented form, the hvdrothecce being long 

 and tubular, with close-set thin, but highly elevated ridges 

 giving a closely annulated appearance to the unusually large 

 hydrothecie. Thuiaria distaiis Allman. in which each inter- 

 node of the stem supports three shallow and distant hj'dro- 

 theca?, and another, probably new, species of the same genus, 

 in which two pairs of hvdrothecEe are borne on each inter- 

 node of the stem, were also included. Two species of the 

 genus DesniDscyphus were found, neither of which can be 

 placed in any species described in the somewhat full literature 

 at m\- disposal. I was greatly interested in finding, while 

 working over this collection a species which was described 

 in 1786 by Ellis, one of the very earliest writers on the 

 hydroids, under the name Serin/ana qnadridoitata^ from the 

 island of Ascension off the African coast. The species is 

 figured in his '-Natural Historv of many Curious and Uncom- 

 mon Zoophytes Collected From Various Parts of the World.'' 

 In 1 82 1 Lamouroux, in his "Exposition Methodique," des- 

 cribes the same form under the name Pasythea qiiadridcntata. 

 From that time on, this curious genus seems to have been 

 lost sight of up to the time when we found our specimens 

 near Little Cat Island. This interesting species is peculiar in 

 having the calicles in groups of four, the lower pair being- 

 larger and somewhat different in shape from the upper. 



No less than twelve species of Plumularid.e are included in 

 the collection made here, and two-thirds of them are probably 

 undescribed. The genus Phinudaria is represented by twa 

 closely related species, both apparently new. Halo^ieris 

 caj'inata Allman is a very pretty species which has the cup- 

 shaped hvdrolheca,^ surmounted by a pair of fixed lateral 

 nematophores borne on long processes from the stem. The 

 name "carinata" was suggested by the keel that runs down 

 the anterior face of the hydrotheca\ The bulkiest hydroid 

 secured during the whole cruise was a species which is in 

 some respects allied to Hippurella; but does not show the 

 peculiar reproductive contrivances of that genus. The speci- 



