/■ -papillo Bul for the stipes-cha the fcwo species 



might be sometimi owing t" the similarity of size <>f the capitulum filaments. 



/' / is distinguished by its hollow compressible stipes and thicker 



Amonj cimens in Herb Mus Paris is a plant of /'. capitatus Lamarck, "coll. 



de Lamarck", I > i ■ usni . and this we figure for its historica! interest (fig [64 . 



iall) short. The comal filaments have a diameter of [50 200 fi (fig. 

 non in the older collections. 



tate of the species is represented in the British Museum b) a diminutive and 



cimen (Jamaica, Humphrey), published under the name <>f Udotea conglutinata 



l'h\ \mer. n" 14S2 and subsi-i|ucntly referred to f', cyathiformis in Collins's Green 



■1' North America ]>. 395. It is a small starveling plant of /'. capitatus with typical 



loporose stipes-cortex and rather thin (Vee comal filaments (100 — 150 ;j., rarely 200 v., in 



diameter). In habit and si/c of plant it corresponds with /'. mediterraneus. 



< >ur f. elongata is. as may be seen in the diagnosis above, founded on /'. elongatus 

 Decne. Mém. sur les Corallines p. 109), the type of which is in Herb. Lamouroux according 

 to I >i 1 visne. We have found specimens under the name *Nesea Penicillus var. Banc de 

 Bahama" in herb. Lamouroux, which exactly fit Decaïsne's description. One "f these speci- 

 mens is represented in fig. [66. Hie difference between these specimens and typical /'. capi- 

 tatus appears to consist in the extent to which the stipes penetrates into the capitulum, and 

 in the thicker comal filaments. In f. typica the stipes seldom reaches the middle of the capi- 

 tulum : in f. elongata it penetrates beyond the middle. In other words, the capitulum-filaments 

 arise from the stipes for a greater distance below the apex in f. elongata than is the case in 

 f. typica. In f. elongata subsidiary mits ol filaments sometimes arise from the stipes below the 

 main capitulum (PI. XIX. fig [66). This form of Penicillus is described and well figured by 

 K rziNG under the name of Corallocephalus barbatus (Tab. Phyc. vol. VII. p. 8, t. 20 fig. 2 . 

 The diameter of the filaments <>f /'. elongatus Decne. is generally about 200 — 300 [j. (fig. 167). 

 whereas that of typical P. capitatus is usually not more than 2007. (fig. [65). There are 

 however many intermediate links between the two forms which cannot be referred with d 

 tainty t" either. We are therefore in doubt whether f. elongata can really be maintained. 



There is sometimes a little difficulty in distinguishing f. elongata from old dried speci- 

 mens of Rhipocephalus oblongus with which there is a strong superficial resemblance. The 

 must trustworthy distinguishing feature is that in Rh. oblongus the characteristic fiabellules can 

 always be found sec fig. 191 ) in the apical cavity of the capitulum even in battered speci- 

 ind at the bases of these fiabellules the dichotomies are closer together than the basal 

 otomies of the comal filaments ol P. capitatus f. elongata. This point is more fully dis 

 under Rh. oblongu 



K i.iN'. has figured a plant in Herb. Sonder under the name of Corallocephalus erio- 



l'ab. Phyc. VIII. 1858. p. 13, t. 2ii fig. Ik, which, judging from the figure, we believe 



an old battered and dishevelled specimen of /'. capitatus. But whether Nesea 



Lamx. (Hist. Polyp Corall. flex. 1816. p. 257) must also be referred to P. capitatus 



