150 Eev. T. Hincks on the Hydroida. 



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

 vated polj^ite and tlie pendent habit. 



II. PODOCORYNE CARNEA, Sars, AND ITS APPENDAGES. 



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



I liave elsewhere noticed* the occurrence on this sjiecies of 

 spiral and filamentary appendages similar to those which are 

 found on llydractinia echitiata, 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 o{ Hydr actinia 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 hydi-anths ;" 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 or tentaculoid appendages : 



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

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



