Coughtkey.— Notes on the New Zealand Hydroidese. 289 



Genus Plumularia, Lamarck. 

 Hydrophyton simple or branched, the branches pinnate, and plumose ; 

 hydrothecse small, sessile and unilateral. 



Plumularia pennatula, Hutton. 



S. pennatvla, Ell. and Sol., Zooph., 56. 

 P. pennatida, Johnst., Brit. Zooph. 



tube 



branches alternately closely pinnate, brown or reddish-brown. 



" Hydrothecse approximated, seated in the axil of a long incurved spine, 

 aperture unequally crenated. Gonangia large, subcylindrical, stalked, with 

 numerous transverse strongly denticulated ribs, situated on the inner side of 

 the branches." 



Captain Hutton describes the long process in axil of which hydro theca is 

 placed as a " spine," but Dr. Johnston's description of it as " a long tubular 

 incurved process" is more correct (see fig. 37). The great length of this 

 process is noteworthy. The aperture of each hydrotheca is more dentated 

 than crenated, and the lower two-thirds of hydrocaulis is naked ; there is a 

 distinct joint in every branch opposite the base of each hydrotheca. Gonangia 

 I have not seen. " Lyall Bay. (F.W.H.) Common." Fig. 37. 



I have not collected any specimens of this species, and am indebted to 

 Captain Hutton for specimens of it. 



Plumularia banksii, Gray. 



Regarding this species there is some doubt. Dr. Gray's description in 

 Dieffenbach's New Zealand, II., p. 294, is as follows : 



" Plumularia banhsii, Gray. 



" Inhabits Dusky Bay, New Zealand. (Sir Joseph Banks). Stem com- 

 pound, branched ; branchlets simple, opposite, pinnate, unilateral, incurved ; 

 cells close, rather crowded, bell-shaped, toothed at the mouth ; vesicles — ? 



"Allied to P. myriophyllum (Johnst., Brit. Zooph., 145, t. 29, figs. 4 

 and 8) but more branched." 



Captain Hutton's description, Trans. N. Z. Inst, V., 1872, p. 259, is 

 different to above. 



" Hydrophyton irregularly branched, composed of several tubes ; branches 

 alternately closely pinnate ; pinnae leaning to one side ; reddish-brown. 

 Hydrothecse approximated seated in the axil of a double incurved spinous 

 process, aperture with an obtuse tooth on each side. Gonangia — ? 



" Lyall Bay (F.W.H.) A single specimen only." 



It is improbable that both of these descriptions refer to the same species, 



be 



Ml 



