648 PROF. W. A. HEBDMAN S EETISED 



be more or less certainly synonyms of oue or other of the pre- 

 ceding species. The following, however, are iraoerfectly known, 

 and still in doubtful case, and may some of them be distinct 

 species : — 



Salfa antarctica, Meyen. (A. Arcfc.) 



8. antheliphora. Per. & Les. (Atl.) 



S. an'pera, Oham. (N. Pac) 



8. bicornis, Oham. (Mai.) 



8. ecsrulea, D. Ch. (Med.) 



8. dubia, Cham. (N. Pac.) 



8. emarginata, Q. & Gr. (Pac.) 



8. hermdea, Dall. (N. Atl.) 



& informis, Q. & G. (Pac.) 



8. pyramidalis, Less. (?) 



8. rhomboides, Q. & G. (Pac.) ■ ■ 



8. rubrolineata. Less. (?) 



8. tricuspida, Less. (?) 



8. trimispidata, Q. & G. (Pac.) 



8. vaginata, Cham. (Mai.) 



Family II. OCTACNEMID^, Rerdman, 1888. 



Body flattened antero-posteriorly (?), probably attached. 



Test gelatinous, thin, transparent. 



Branchial sac with no stigmata or openings into the peri- 

 branchial cavity. 



Alimentary canal placed dorsally and posteriorly ; coiled up 

 along with the reproductive organs to form a visceral mass or 

 " nucleus." 



Life-history unknown. 



This family contains only the remarkable deep-sea genus 

 Octacnemtcs, discovered during the ' Challenger ' Expedition. 



OcTACNEMTTS, Moseley, 1876 {Herdman, 1888). 



Body flattened antero-posteriorly (?), probably attached by the 

 posterior end. Margins of body prolonged to form 8 conical 

 radiating processes. 



Test gelatinous, thin, transparent. 



Mantle slight. Musculature in the form of narrow muscle- 

 bands, which are mainly confined to the conical processes 



Branchial sac with its length directed dorso-ventrally, and having 



