ABT. 13 BEYOZOAN FAUNA CANU AND BASSLER 39 



Affinities. — The tuberosities are directed obliquely on the aper- 

 tura ; they modify the exterior aspect. 



The operculum is transverse in the form of a bell, somewhat 

 sinuate laterally. The muscular attachments are very narrow and 

 close to the border. In its frontal tuberosities this species is close to 

 Lepralia twrrita Smitt, 1873, but differs in its rather regularly 

 hexagonal cells and its porous frontal. 



Only the figured specimen was found; it was living but not ovi- 

 celled. 



Occurrence. — Galapagos Islands, D. 2813. 



Holotype.—QdX. No. 8513 U.S.N.M. 



HOLOPORELLA POROSA, new species 



Plate 6, Fibres 7, 8 



Description. — The zoarium is globular, hemispheric, fixed to nulli- 

 pores. The zooecia are distinct, separated by a furrow, orbicular or 

 polygonal; the frontal is convex and covered with large scattered 

 pores. The apertura is median, semielliptic, somewhat elongated 

 with proximal, concave border. The ovicell is very large and convex, 

 with a median area covered by pores smaller than those of the 

 frontal; it is never closed by the operculum. 



Measuremen ts. — 



fA« = 0.22mm. 

 Aperturaj^^^O 18-0.20 mm. 



Acuities. — This species differs from HoloporelJcb hexagonalis in 

 the absence of tuberosities around the apertura and in the special 

 nature of the muscular attachments of the operculum. 



The operculum is light colored and rigid. It has the form of a bell 

 with a very concave proximal border. The muscular attachments 

 are much thickened and each terminates in a point. 



Biology. — The single specimen dredged was living and ovicelled 

 April 9, 1888. ♦ 



Occurrence. — Galapagos Islands, D. 2815. 



Holotype.—C?it. No. 8514, U.S.N.M. 



HOLOPORELLA TRIDENTICULATA Busk, 1881 



Plate 7, Figures 2, 3 



1881. Cellepwa iridenticulata Busk, Note on the chitiuous organs in the Cheilo- 

 stomata, Journal Linnean Society, vol. 15, p. 347, pi. 26, fig. 9. 



1884. Cellepora tridenti(ni.lata Busk, Challenger, p. 188, pi. 29, fig. 3 ; pi. 35, fig. 



17 (operculum). 



1885. Cellepora tridcnticulata Waters, Aklinga, Quarterly Journal Geological 



Society, vol. 41, p. 306. 



1886. Cellepora tridenticiilata MacGiixivkay, Prodromus Zoology Victoria 



decade 13, p. 110, pi. 128, fig. 3. 



