422 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



HOLOPORELLA PILAEFERA, new species 



Plate 60, figs. 2-6 



Description. — The zoarium is large, unilamellar greenish, it creeps 

 most often over the debris of shells and the pebbles of the bottom. 

 The superficial zooecia are distinct, very convex, rarely entirely 

 erect; the frontal is finely granular; it bears an enormous cylindrical 

 beak, very salient, very long, in the form of a pillar. The apertura 

 is a little transverse; the peristome frequently bears a more or less 

 salient avicularium. The ovicell is globular, granular, its orifice is 

 large. The zoarial avicularium is relatively small ; its beak is spatulate. 



o a 



8 



Fig. 165. — Holoporella pilaefera, new species 



A, B. Mandibles of spatulate zoarial avicularia, X85. C. Operculum of 

 superficial zooecia, X85. D, E. Mandible of two types of interzooecial avicu- 

 laria, X85. 



Measure in e nts. — 



a™~+ [k = 0.16ram. v • | £2 = 0.45-0.65 mm. 



Apertura' Zooecia! 



IZa = 0.22 mm. Us = 0.40-0.50 mm. 



Length of avicularium = 0.35 mm. 



Variations. — The size of the colonies varies from 2 to G square 

 centimeters; they are alwa} 7 s convex and irregularly undulated. On 

 certain zoaria the pillars are very frequent, on others they are very 

 rare. The operculum is very thin, very fragile and difficult to prepare. 

 It is curtailed laterally and the muscular attachment are little 

 apparent. 



The length of the mandibles of the zoarial avicularia is very varia- 

 ble; thcv can measure 1.5 mm. in length. 



Affinities. — This new species differs from Qettepora Jionolulensis 

 Busk, 1884, in which the frontal is also granulose in the presence of 

 its large cylindrical beak. It differs from Holoporella joliata Mac- 

 Gillivray, 1888, from Australia in its spatulate mandibles, in the loss 

 salient and less acuminate oral umbo and in its unilameller zoarium. 



Biology.— -Out living specimens were in reproduction February 

 15-18, 1908 (16-32 meters). They have been dredged in waters of 

 little depths. The larger colonies bristling with a large number of 

 columnlike beaks have been dredged only at 16 meters depth. The 

 colony dredged at 388 meters was multilamellar, dead and in bad 



