'47 



Fam. Horneridae Smitt. 



Horneridae Smitt, 1866, "Krit. förteckn. Skand. Hafs-Bry.", II. Öfv. K. Vet.-Ak. Förh., XXIII, 



p. 404. 



Hornera Lamx. 



Hornera Lamouroux, 1S21, u E\-p. Méth.", p. 41. 



Hornera Lamouroux, 1827, "Encycl. Méthod.", "Zooph.", p. 460. 



1. Hornera spinigera Kirkp. (Fl. XI, figs 8 — 13). 



Hornera spinigera Kirkpatrick, 1888, "Pol. Mauritius", Ann. May.. Nat. Hist. (6) I, p. 83, 



PI. X, figs i — i/;. 

 Hornera spinigera Philipps, 1899, "Polyzoa", WlLLEV's ''Zool. Res.", Pt IV, pp. 441, 449 (Lifu). 



470. B. Stat. 97. 5°48'.7 N., ii9°49'.6E., 564 Metres; coarse coral-sand. 



82. A. Stat. 105. 6°8'N., i2i°i9'E., 275 Metres; coral-bottom. 



483. B. Stat. 117. Kwandang Bay, entrance, 80 Metres (chart) ; sand and coral. 



112. B. Stat. 156. o°29'.2S., I30°5'.3E., 469 Metres; coarse sand and broken shells. 



Also (Univ. Mus. Zool., Cambridge) : — 



Lifu, Loyalty Islands, A. WlLLEV Coll., Reg. Mar. 1, 1898 (determined by Miss E. G. PHILIPPS). 



Zoarium usually branching in one plane, the branches numerous and close together, 

 alternate or nearly or quite opposite. Spines developed on many parts, including the peristomes. 

 Basal surface of the young branches with strong longitudinal ridges, between which the surface 

 is concave and bears a row of pores. In the older branches the ridges become confiuent, 

 more numerous and less regular, the pores being still distinguishable. On the frontal surface 

 the zooecia are arranged in Tuóu///>ora-Yike alternate series, each of which consists of 2 or 3 

 zooecia, the outermost the most prominent. Peristomes spinous, some of the spines radiating 

 inwards towards the centre of the orifice. The spines are most developed on the outer zooecia, 

 and a pair of specially long ones are often produced by the distal margin of the peristome, 

 and a large spine by the middle of the proximal border. This suboral spine may be greatly 

 developed, and is sometimes as long as the peristome. Ovicells on the basal surface, extending 

 along the region of two consecutive branches, their basal surface reticulato-punctate and more 

 or less strongly carinate. Ooeciostome visible in the frontal view, situated in the axil of a branch. 



This very beautiful and characteristic species has been well described by Kirkpatrick 

 from specimens found at Mauritius; and it has also been recorded from Lifu by Miss Philipps. 

 It is specially characterised by the serial arrangement of its zooecia and by the spines which 

 occur on various parts, particularly on the peristomes. In the 'Siboga' specimens the series 

 are usually bizooecial ; but in that from Lifu three zooecia generally occur in a series. The 

 outer peristome is long and free, while the inner zooecium has its orifice almost level with 

 the surface of the branch. 



The branches of this species are developed very freely, succeeding one another with but 

 small intervals between them. They are given oft by both sides of an older branch and may be 

 alternate, opposite or nearly opposite one another. Most of the branches are in one plane. 



At the growing tips (fig. 9) the zooecia are very distinct. Their frontal surface is here 



147 



