[48] iin. JAMES RITCHIE ox HTDROIDS [^^'^Y 28, 



showing in optical section a manulirium surrounded bv a horse- 

 shoe-shaped mass of generative plasma. In onl_v one gonophoie 

 of the many examined was there a trace of actinula-formation, 

 tentacles being indicated b_y apparently about 8 filaments. 



Locality St. Vincent, Cape Verde Islantls. Found on bottom 

 of a lighter, 30th July, 1904. 



Previous record, off K^atal coast. 



Family C l A v I d ,e. 

 SoLExioPsis *, gen. nov. 



Type. S. dendriformis, sp. n. 



Gen-i;ric characters. — Trophosome. Colonies branched and 

 fascicled. The branches originate from the division of a cceno- 

 .sarcal strand into two portions which lie parallel and close to one 

 another for a considerable distance, each becoming sheath eil in a 

 chitinous perisarcal tube, the outermost stitind finallv bends out- 

 wards and becomes free to form a bi-anch {i-ide text-fig. 142, p. 496). 

 The hydi-anth-bearing ramuli originate in the same way as the 

 branches. Hydrauths cylindrical, with club-shaped proboscis 

 and many scattered filiform tentacles. 



Gonosome. — The reproductive bodies are pernianentlv fixed 

 gonophores of a simple type. They are blind .sacs arising from 

 the ccenosarc some distance beneAth the hydranth and Iving 

 within the perisarcal tube from which the hydranth projects. The 

 ova are developed in the wall of the sac. 



The genus Soleniopsis is distinguished by its peculiar mode 

 of branching and by its gonophore. The branching, which is 

 more fully de.scribed in the discussion on the species, appears to 

 be similar to that of Corydendrium (Weismann, 1883). I have 

 not seen the original description, but Dr. Fowler says with regaid 

 to the branching of the genus, " The young buds, instead of 

 breaking through the perisarc and growing oiitwards as is usual, 

 gi-ow upwards for some distance inside it and surround themselves 

 with secondary perisarc " (Fowler, 1900, p. 13); and this agrees 

 with the structure in the present genus. Corydendrium differs 

 from Soleniopsis. however, in having gonophores which give rise 

 to free medu.sie (Delage, 1901). 



The gonophores here ai-e of great length and of extremely 

 simple structure. Tiiey are also peculiar in Iving within, ami thus 

 being protected by, the tube which contains the trophosome, 

 instead of bursting through the perisarc and forming hernia-like 

 globular projections like most other gonophores. The ova and 

 .spermatozoa apparently escape from the mouth of the tube, 

 pa.ssing between the swollen bulb beneath the neck of the hydranth 

 and the perisarcal wall. 



On account of the scattered filiform tentacles on the hydranth 



* The name of the genus, Solenio-psis, is intended to sugg:est the resemblance 

 hetweeu the jjarallel-h ing cueuosarcal strands of the colony and the "solenia" of 

 Alcyonarians. 



494 



