EEPORT ON THE SIPHONOPHORiE. 255 



Gonophores. — The sexual medusomes are placed at the distal base of the siphosome, 

 below and inside the siphons. There seems to be a couple of clustered gonodendra (a 

 male and a female) attached to the base of each siphon, composing with it (and with 

 the appertaining palpon and bract) an ordinate monoclinic cormidium. The gonostyle 

 of the male as well as of the female gonodendron is richly branched, the number of 

 gonophores large, their size small. The spermaria are oblongish, the ovaria roundish, 

 as usual.. The umbrella is reduced. The special structure of the gonophores, which 

 I could not sufficiently examine, seems to be similar to that of Physophora. 



Genus 546. Sphyrophysa, 1 L. Agassiz, 1862. 



Sphyrophysa, L. Agassiz, Contrib. Nat. Hist. U. S., vol. iv. p. 368. 



Definition. — Nectalidse with a quadriserial nectosome, composed of four cruciate 

 rows of nectophores. Cnidosacs of the tentilla with three terminal appendages, an 

 odd median ampulla, and two lateral horns. 



The genus Sphyrophysa was established by L. Agassiz for the Physonect which Quoy 

 and Gaimard had found in the Tropical Atlantic (lat. 7° N.) in February 1829, and 

 figured under the name Physophora intermedia (2, p. 56, pi. i. figs. 10-18). As far as 

 it is possible to recognise it from their incomplete representation, it seems to be closely 

 allied to the preceding Nectalia, but differs from it in two essential characters of 

 generic value. The nectosome seems to be composed not of two opposite, but of four 

 cruciate rows of nectophores (as in Discolabe among the Physophoridse). The cnidosacs 

 of the tentilla are tricornuate, and bear at the distal end an odd median vesicle and two 

 paired lateral horns (as in Agalrna, &c). 



L. Agassiz also has placed in the same genus, Sphyrophysa, the similar Physonect 

 which Huxley had described as Agalrna breve (9, p. 75, pi. vii.). But this species is 

 probably a true Agalrna, and more allied to the form which Leuckart has described as 

 Agalrna clavatum (compare above, p. 226). 



Family XVI. Discolabid^e, Haeckel, 1888. 



Biscolabidx, Hkl., System der Siphonophoren, p. 41. 

 Physophoridse, Huxley, et niultor. autor. 



Definition. — Physonectee polygastricse, with a short vesicular stem of the siphosome, 

 bearing numerous siphons and a corona of large palpons (instead of the wanting bracts), 

 each siphon provided with a branched tentacle. Nectosome with two, four, or more rows 

 of nectophores. Pneumatophore with radial pouches. 



1 Sphyrophysa = Hammer-bladder, o-ipSj*, qsvoa.. 



