2. HORNKKA. 17 



a. Species uitk durgal uuacia ; antvrior siirfuce /o/H/ifudi/uilli/ Jibrillidcd 

 or sidcate. 



1. Hornera frondiculata, Lamx. (Plate XX. figs. 1, 2, 3, 6.) 



Branches tapering, more or less iu one plane, cylindrical or sub- 

 compressed ; anterior surface strongly fibro-rcticulate, presenting 

 rhomboidal spaces in which are situated the openings of the zoooecia 

 surrounded by numerous pores : mouth of tubes exserted, usually 

 bifid ; dorsal surface coarsely reticulate, granular or nearly smooth, 

 with small elongated pores in the sulci ; oooecium oblong, carinate, 

 ribbed ; aperture tubular, superior. 



Hornera frondiculata, Lamx. Exposit. p. 41, pi. 74. figs. 7-9; M.- 

 Ediv. I. c. p. 17, pi. 9. figs. 1-1 c; Blainv. Man. d'Actinol. p. 419; 

 Heller, I. c. p. 124. 



Retepora frondiculata, Lamk. 



PMillepora tubipora, Ell. i^- Sol. p. 139, pi. xxxi. fig. 1. 



Millepora lichenoides, Linn., Pallas, Esper. 



? Hornera affinis, M.-Ediv. I. c. p. 9, pi. x. fig. 1. 



? Hornera andegavensis, Michelin, Icon. Zoojihi/t. p. 318, pi. 70. fig. 8. 



Hornera serrata et tubuIosaP, Meneghini, I. c. p. 10. 



Hah. Mediterranean, Adriatic (very abundant). Fossil in the 

 Crag and Upper Tertiaries of Sicily &c. 



2. Hornera lichenoides, Linn. (sp.). (Plate XVIII. figs. 5, 0.) 



Zoarium irregularly dichotomous ; branches crowded ; anterior 

 surface faintly fibro-reticulate, sparsely punctate ; opening of zoo- 

 oecia in front of branches circular, and either wholly immersed or 

 slightly prominent, those on the sides of the branches tubular ; 

 orifice elliptical, entire, the border being produced on one side ; dor- 

 sal surface finely sulcate, with minute pores in the sulci ; oocecia 

 dorsal, subglobular ; surface reticulate or coarsely punctured ; aper- 

 ture tubular, lateral. {Alder.) 



" Corallium," Pontoppidan, Norges Natuurl. Hist. i. p. 2o8, pi. 14. 



figs. D, E. 

 Millepora lichenoides, Linn. ; Miiller, Prodroin. p. 252. no. 3046 ; 



Strom, Act. Hafn. xii. p. 309, pi. iii. fig. 12 ; Fabricius, Zool. Sanunl. 



(MS. Smitt), k Faun. Grant, p. 432 (non Pallas). 

 Hornera frondiculata, Sars, Reise Loff. Finm., Nyt Magazin f. Nat. 



Vid. t. vi. p. 146 ; Ptisk, Ann. N. H. 2 ser. xviii. p. 34, pi. i. fig. 7. 

 Hornera borealis, Busk, Crag Polyzoa, pp. 95 & 103; Alder, New 



Brit. Polyzoa, Mic. Journ. new ser. vol. iv. p. 108, pi. v. figs. 1, 6. 

 Hornera lichenoides, Smitt, I. c. p. 404, pl.vi. fig. 10, pi. vii. figs. 1-14. 



Hah. Arctic Seas (Loven) ; coast of IS'orway (Pontopjj., Sars, 

 M^ Andrew) ; Shetland (^Barlee). 



3. Hornera csespitosa, n. sp. (Plate XV.) 



Zoarium densely and irregularly branched in all directions ; 

 secondary branches short and truncate ; anterior surface obscurely 



