10 Proceedings of the Royal Irish Academy. 



family EUiselladae placed Juncella, Ellisella, along with many others which 

 do not concern us here ; at the same time he re-established the genus 

 Ctenocella, and formed a new one, viz., Viminella, in the same family. 



The genus Scirpearia he relegated to a heterogeneous group, which he 

 called the Oaligorgiadae, in which he established the genus Nicella, to 

 include his Scirpearia dichotoma. The following synopsis brings out the 

 general plan in this classification : — 



Family ELLISELLADAE. 



Juncella. — Coral simple, sub-compressed near the base ; branches sub- 

 cylindrical, with a more or less distinct lateral groove, especially at the base. 

 Axis continuous, opaque, solid, calcareous, hard at the base, white and softer 

 above. Bark, when dry, granular, thin, with numerous series of sunken or 

 slightly prominent polypiferous cells on each side of the stem and branches : 

 J. juncea. 



Ellisella. — Coral tree-like, furcately branched ; branches spreading and 

 then ascending ; lateral groove very narrow, but well marked ; the rest like 

 Juncella: H. elorigata; E. coccinea; JE. gemmacea; E. calycnlata. 



Ctenocella. — Coral branched, fan-like, expanded in a plane ; branches 

 with a series of virgate branchlets on the upper side ; lateral line well 

 marked, but narrow : C. pedinatn. 



Viminella. — Coral simple, elongate, liagelliform. Bark thin ; lateral 

 space broad, with a sunken line. Polyps-cells, cylindrical, pi'ominent, in 

 three or four series on each edge of the stem. Axis grej', calcareous : — 



V. juiicea = J. vimen. 



V. flagdhim - J. extaiis and J. Jfagellum. 



V. hystrix = J. hystrix. 



V. laevis = J. laevis. 



Family OALIGORGIADAE. 



Scirpearia. — Coral slender (simple or sub-simple), rod-like. Axis 

 slender, cylindrical, hair-like, solid, white, calcareous, attached by a broad 

 base. Bark (when dry) thin, smooth, granular, with a series of sub-cylindrical, 

 polypiferous cells placed alternately on each side of the stem. Lateral groove 

 indistinct. S. mirabilis, S. fv.niculina, S. hariadensis, S. monillifoi'mis. 



Nicella. — Coral fan-like, on one plane, branched ; branches forked, rather 

 diverging. Bark smooth, brown. Polyps-cells cylindrical, truncated, diverg- 

 ing from the stem at nearly right angles, mouth open. Axis calcai'eous, 

 white, solid. N. mauritiana. 



