PLATE XXIII. 



The figures of this Plate were drawn by me from living specimens in the Canary Island Lanzerote, 



December 26, 1866. 



Nectophysa ivyvillei, n. sp. (p. 327). 



Diam. 



Fig. f 1. A complete corm, in the expanded state, quietly floating on the surface. 

 p, Pneumatophore ; po, its apical stigma ; pv, hypoeystic villi ; a, 

 trunk ; s, siphons ; t, tentacles ; ga, gonodendra, . . . nat. size 



Fig. 2. A complete larger corm, in the expanded state, with twisted trunk, 

 reposing on the bottom of the glass vessel. The suctorial mouth- 

 discs of the lower siphons are attached to the wall of the vessel. 

 Characters as in fig. 1, . . . . . nat. size 



Fig. 3. A complete corm (the same as fig. l) in the contracted state, with 

 shortened and thickened trunk, coiled up in a dexiotropic spiral. An 

 air-bubble (x) is being expelled through the apical stigma (po) of 

 the pneumatophore ; pf, pneumatocyst ; pp, pigment-cap (mitra 

 ocellaris) ; pv, hypoeystic villi, . . . . . x 4 



Fig. 4. Uppermost portion of the fully contracted trunk. The pneumatocyst 

 (pf) is nearly evacuated and the greatest part of the gas expelled 

 through the apical stigma (po). The hypoeystic villi (pv) are 

 thrown into the vesicular inflated apical portion of the trunk (a) ; 

 i, buds; ga, gonodendra ; s, siphons, . . . x 10 



Fig. 5. A single siphon, with its tentacle (t) attached to the trunk (at) ; ts, 



tentilla, . . . . . . . x 20 



Fig. 6. A small portion of a tentillum. kc, Cnidocysts ; tw, palpoblasts, . x 300 



Fig. 7. A single cnidocyst with the included cnidofilament, . . . x 900 



Fig. 8. A single branch of a gonodendron. gq, Gonopalpon ; h, androphores ; 

 hx, spadix ; hs, sperma; /, gynophore; fm, its rudimentary manu- 

 brium; uw, subumbrellar cavity, . . . . x 50 



