512 MR. JAMES RITCHIE ON HYDROIDS [May 28, 



The mesial nematophore is long (almost 0-3 mm.), i-e&,ching 

 0'05 mm. above the level of the hydrathecal margin, adnate for 

 little more than half its length, and with two apei'tures. The 

 supracalycine nematophores are divergent, long and tubular, 

 inclined at an angle similar to that of the mesial nematophore. 

 and rising a short distance above the margin of the hydrotheca, 

 to which they are adnate. On each stem-internode there are two 

 triangular nematophores, one proximal, the other distal to the 

 base of the hydroclade, while the base itself bears antei-iorly a 

 tubular nematophore. 



Oonosorae. — The gonangia are borne or modified recurved 

 hydrocladia, divided into about ten short intei-nodes, the proximal 

 bearing a hydrotheca, which is replaced on the following two or 

 three internodes by a gonangium. Each of the remaining inter- 

 nodes bears one or two divergent tubular nematophores, each with 

 two apertures, one terminal, the other in the angle formed between 

 nematophore and internode. The gonangia are almost circular, 

 and ai-e much compressed. As many as twenty-two gonangia on 

 eight phylactocarps wei-e counted on one specimen. The arrange- 

 ment of the nematophores on the phylactocarp suggests that which 

 occurs in connection with the hydrothecfe, two divergent nemato- 

 phores frequently occuri-ing at the same level and beneath them 

 a single mesial nematophore. 



Loccdity. Growing on a leaf found in a bottle containing 

 tunicates from Mattiota, St. Vincent Harbour. 



The trophosome of the present species is almost identical with 

 that of Aglaophenia plumosa Bale (1884), but there the recurved 

 gonangial pinna bears " 15-20 pairs of alternate pinnules," these 

 again bearing the nematophores which are arranged differently 

 from those in the specimen before me, the whole structure forming 

 a corbula. 



List of Literature cited. 



Alder, J., 1859.— "Description of two new Species of Sertularian 



Zoophytes, found on the coast of Noi'thumberland " ; Ann. 



Mag. Nat. Hist. 3rd ser. vol. iii . 

 Allman, G. J., 1864. — "Notes on the Hydroida"; ihid. 3rd ser. 



vol. xiv. 

 Allman, G. J., 1871, 1872. — A Monograph of the Gymnoblastic 



or Tubularian Hydroids. Hay Society. London. 

 Allman, G. J., 1877.^" Report on the Hydroida collected during 



the exploration of the Gulf Stream." Harvard Mus. Zool. 



Mem. 5. 

 Allman, G. J., 1883. — "Report on the Plumularians." 'Chal- 

 lenger' Expedition, Sci. Reports, Zool., vol. vii. 

 Allman, G. J., 1888. — " Report on the Hydroids," Part II. ; ihid. 



vol. xxiii. 

 Bale, W. M., 1884.— A Catalogue of the Australian Hydroid 



Zoophytes. Sydney. 

 Beneden, p. J. VAN, 1844. — " Recherches sur TEmbrj^ogenie des 



Tubulaires" ; JSfouv. Mem. de I'Acad. de Brux., tome xvii. 

 BiLLARD, A., 1904. — "Contributions a I'etude des Hydroi'des"; 



Ann. des Sci. Nat. ser. 8, vol. xx. 



