FROM THE LOYALTY ISLES, NEW GUINEA AND NEW BRITAIN. 447 



in rows radiating from the centre and being separated by depressed lines marked by 

 small indentations; surface smooth and shining. Orifice sub-central, surmounted by 

 eight spines. Operculum coarctate with an arched upper margin and a slightly convex 

 lower margin. Placed far back on each side of the orifice a minute avicularium on 

 a small elevation, mandible rounded, and directed inwards and upwards. Distributed 

 over the zoarium, other minute oval avicularia with rounded mandibles. 



Ooecia ? 



Measurements : zooecium •82 mm. in width x "SI mm. in length, operculum "08 mm. 

 in width x '11 mm. in length. 



This species which is here represented by a single colony also occurs in the collec- 

 tion from ToiTCs Straits which Dr Haddon has presented to the Cambridge University 

 Museum of Zoology. It l)ears a superficial resemblance to Lepralia tuber culata, the 

 species described above, but is distinguished from it by the shape of the zoarium, 

 the size and shape of the opercula and the form of the avicularia. 



36. Smittia marmorea, Hincks. PI. XLIII., fig. 10. Hincks, Brit. Mar. Pol., p. 350. 



The collection contains one small fragment which seems to correspond with 



Hincks' species. The sinus in the lower margin of the secondary orifice is broad and 



the notches on each side are very prominent. The pores at the edge are very large 



.and the avicularia are longer than in Hincks' species, extending the whole length of 



the zooecium. 



No ooecia are seen on this fragment. 



37. Mucronella articulata, n. sp. PI. XLIII., fig. 11. 



Zoarium disc-shaped and encrusting. Zooecia arranged in lines, the cells being 

 indistinctly separated from one another ; the surface finely granular. Orifice orbicular 

 and below it a small mucro ; round the orifice eight long jointed spines standing up 

 vertically ; each spine consisting of three joints, the terminal segment ending in an 

 expanded funnel. Placed high up, one on each side of the orifice in the younger 

 zooecia, two minute avicularia with rounded mandible dii-ected inwards. Distributed 

 over the zoarium, large vicarious immersed avicularia with broad duck-bill shaped 

 mandibles. 



Ooecia ? 



Measurements : zooecium "42 mm. in width x 26 mm. in length, operculum 

 •1 mm. X "1 mm. 



The characteristic feature of this species is the presence of jointed spines with 

 the terminal segment expanded into a funnel. In most of the central zooecia only 

 the two lateral spines have this cup-like termination, the remaining six being shorter 

 and possessing ends which are not expanded but often pointed. However the fact that 

 most of the marginal zooecia possess eight spines with expanded ends suggests that 

 the others have lost their terminal joint. 



There are three colonies of this species. 



60—2 



