REPORT ON THE HYDROIDA. 



43 



In all the specimens examined the phylactocarps were enveloped in a glairy mass, 

 insoluble in boiling water, Ijut completely soIuIjIc in a solution of caustic potash. I have 

 no doubt of this being the remains of the protoplasmic contents of the nematophores, and 

 that in the living state it had been emitted as pseudopodial outflows from the cup-shaped 

 nematophores here so largely developed. 



I believe that the present species must be identified with the Aglaophenia {Lyto- 

 carpia) secunda of Kirchenpauer,^ though in some points, especially in the form of the 

 hydrotheea and of the comb-like phylactocarps, it can scarcely be brouglit into complete 

 accordance with Kirchenpauer's figures. Kirchenpauer's specimens were obtained in the 

 South Sea, the China Sea, and the Pelew Islands. From the last-named locality they 

 were brought by Semper, who, according to Kirchenpauer, regarded the species as one of 

 those so much dreaded by the natives on account of its stinging properties. 



The limits of the plate would not allow a figure to l^e given of more than a portion of 

 the entire Hydroid. The Challenger collection contains a specimen which is more than 

 two and a half feet in len2;th. 



Dredged off Zamboauga, Phihppines, 30th January 1875, from a depth of 10 fathoms. 



Lytocarpus spectahUis, n. sp. (PI. XV.). 



Trophosome. — Colony attaining a height of five inches ; main stem strongly fascicled 

 sub-dichotomously branched, the branches closely set with opposite primary pinnae, which 

 are fascicled at their origin, and destitute of hydrothccre, but which carry the alternately 

 disposed hydrocladial pinnae ; hydrocladia about ono-tentli of an inch in length, borne 

 also by the main stem in the intervals of the primary pinnse. Hydrothecse wide, 

 with undulated margin, an anterior parietal fold, and a very short intrathecal ridge ; 

 mesial nematophore thick, adnate t(3 the hydrotheea walls for somewhat more than half 

 their height, and then continued as a strong, free, spine-like process, which slightly 

 overtops the hydrotheea margin, and has a lateral as well as a terminal aperture ; lateral 

 nematophores spine-like, conical, overtopping tlie hydrotheea. 



Gonosome. — Phylactocarps given off at intervals among the hydrocladia, each replac- 

 ing a hydrocladium, and consisting of a jointed rachis composed of some eight or nine 

 internodes, the proximal internode carrying an ordinary hydrotheea, and each of the 

 following internodes sending off" two opposite, strong, conical spine-like processes, each 

 with a terminal and a lateral orifice. Gonangium nearly sessile, borne by the modified 

 second internode of the rachis. 



Lytocarpus spectahUis is a beautiful bipinnate form, and present-s in its details several 

 features of interest. The margin of the hydrotheea, instead of presenting the serrated ■ 

 condition usual among the phylactocarpal Plumularidw, is merely sinuous, while the 



' Kirchenpauer, he. cit., p. 35, pis. i.-iii. 11,^. 1.j. 



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