150 Rev. T. Hincks on the Hydroida. 



covering. The striking features of the species are the large ele- 

 vated polypite and the pendent habit. 



II. PODOCORYNE CARNEA, SarS, AND ITS APPENDAGES. 

 (PI. XII. figs. 7 & 8.) 



I have elsewhere noticed * the occurrence on this species of 

 spiral and filamentary appendages similar to those which are 

 found on Hydractinia echinata^ Fleming, and which were first 

 described by the late Dr. Strethill Wright. In his work on 

 the Tubularian Hydroids, Prof. Allman has suggested a doubt 

 as to the real nature of these appendages. Neither kind, he 

 tells us, was present in any of the specimens that came under 

 his observation ; and he adds, " whatever be the nature of the 

 spiral bodies observed by Hincks, they certainly do not possess 

 the constancy which characterizes the spiral appendages of Hy- 

 dractinia ] and it is difficult not to regard both the spiral bodies 

 and the tentacular-like filaments observed by Hincks in Podo- 

 coryne as merely abnormal alterations of the ordinary hy- 

 dranths" (polypites) f. 



First, then, as to the spirals. There can be no doubt 

 about their occurrence on Podocoryne carnea^ as I have now 

 in my collection a well-developed specimen on which they 

 are present, forming a line along that portion of the basal 

 crust which edges the mouth of the shell supporting the 

 colony. They are usually curled up in two or three coils ; 

 they have a white central core, and are rounded off and 

 slightly clavate at the top, which glitters with thread-cells. 



Allman seems to think that they are much more frequently 

 wanting than the similar bodies in Hydractinia^ and regards 

 the inconstancy of their occurrence as a proof of their abnor- 

 mality. But, according to my experience, the spiral appen- 

 dages of Hydractinia are by no means constant ; on the con- 

 trary, they are only present, I believe, on very fully matured 

 colonies ; and in numerous instances I have failed to find them. 

 This seems to be the case also with Podocoryne. 



No doubt all these appendages must be regarded as "altera- 

 tions of the ordinary hydranths ;" but I can see no more 

 reason for considering them " abnormal " in Podocoryne than 

 in Hydractinia. They present the same general appearance 

 and occupy the same position in both ; and in both they seem 

 to be developed only on mature colonies. 



Secondly, as to the filamentary ox tentaculoid appendages : 



* ' History of British Hydroid Zoophytes,' i. p. 32. 

 t ' Gymnoblastic Hydroids/ part ii. p. 350. 



