^Q ZOANTHARIA 



Synopsis of the /sosoanl/ius-species described here. 



A. Single polyps or small colonies of two specimens with tube or groove-shaped coenenchyme, which is 

 well-developed, but probably unattached. The mesoglrea. of the body-wall contains few cells excep- 

 tionally cell-islets. Number of mesenteries 28—32 bulbostis. 



B. Single polyps or small colonies of densely placed polyps connected by an inconsiderable coenenchyme. 

 The polyps are elongated, slightly attached. 



a. Mesogloea of body-wall contains few small cells. Number of mesenteries 32 — 36. Specific 



nematocysts in the filaments 31— 38/i x 11 — \2 n arborcscens. 



aa. Mesoglrea of body-wall contains numerous, granular, fairly large cells. Mumber of mesenteries 

 ^4 — .•^8. Specific nematocysts in the filaments 36 — 53 ;/ x 12// davisi. 



C. Colonies with large, fairly well-developed ccvnenchyme. 



b. Elongated, small polyps. 



c. Number of mesenteries about 34. Specific nematocysts in the filaments partly large 

 26 — 34/1 X 10 — i2/i partly smaller \\fx x 5fi- Well developed cccnenchyme tube-shaped 

 covering needles of Hexactinellidae (always?) islandicus. 



cc. Number of mesenteries about 30 Specific nematocysts in the filaments j^artly large 

 19 — zbfi X 10 — 12 /i, partly smaller 12 — 14/^ x 5 — 6ju. Coenenchyme band-like (on Cidaris 



spines, always?) diibms. 



bb. Polyp of moderate length or .short. 



d. Number of mesenteries 18 — 22. Specific nematocysts in the filaments 22 — 26 // x 7 ^. 

 Mesoglcea of the body-wall almost homogeneous witli very scarce cells. Ccvneuchyme 

 band-like, branched dmticns. 



dd. Number of mesenteries about 32. Specific nematocysts in the filaments partly large 

 31— 43/i X i2/i, partly smaller 15^^ x "] 11. MesogLta of the body-wall contains numerous 

 small cell-islets and less numerous large cell-islets often fused together to form lacunae. 



Cccnenchyme band-like, branched inagiiiiisulosus. 



ddd. Number of mesenteries 38—40. Specific nematocysts in the filaments partly large 

 41— 48/t X 14— 17/i, partly smaller 17 — 19/^ x 7 /^ Mesogloea of body-wall contains 

 numerous small cell-islets and scattered large ones. Lacunae-system slighth- developed, 



ccenenchyme of small dimensions multinsulosus. 



dddd. Number of mesenteries 38 — 40. Specific nematocysts in the filaments partly large 

 31— 40// X 12 — 14(19)//, partly smaller 17 — 19// x 7//. Mesogloea of body-wall contains 

 numerous, often elongated cells and larger or smaller cell-islets sometimes fused together 

 at the base of the mesenteries. Large, thin ccruenclnme ingolfi. 



Isozoanthus bulbosus n. sp. 



V\. I, figs, 5, 6. PI. 2, figs. 14 ~:6. PI. 6, fig. i. 



Occurrence: 65°34'N., 7°3i'W. 762 Danish fathoms. Bott. temp. — o-8°. St. 105 Ingolf Ex. 

 Several specimens. 



