ART. 13 BRYOZOAN FAUNA CANU AND BASSLER 45 



supports an avicularium placed in a proximal angle. The opesiiim 

 is suborbicular and restricted laterally by two large condyles. The 

 ovicell is large, salient, smooth, marginated proximally, with a very 

 large orifice; it is often decorated by one or two avicularia in which 

 the beak is always turned inferiorily. The avicularia are long, thin, 

 triangular, without pivot; when there is one only it is placed trans- 

 versely, but when there are two their beak is oriented distally. 

 Measurements. — 



^ . f7iO = 0.15-0.20mm. ^ . Zs = 0.40-0.40 mm. 

 Opesium , n nn A r>o Zooecium 



^ H<?=0. 20-0. 23 mm. ?s = 0.45 mm. 



, . , . fZa'y = 0. 20-0. 25 mm. 

 Avicularmm I -, „ ^„ 



I lav = 0. 10 mm. 



A-ffimties. — In its exterior aspect this resembles Ghaperia annulus 

 Manzoni, 1875, very much, but differs from it in the presence of two 

 condyles to the opesium, in having six spines and not four, in the 

 simple spines (and never bifurcated), in the avicularia irregularly 

 oriented and never placed in the median axis of the zooecium, and in 

 the frequent occurrence of two avicularia on the ovicell. It differs 

 from Ghaperioo galeata Busk, 1854, in the absence of bifurcated 

 spines. Moreover, this species is rather poorly known because of the 

 erroneous interpretations of the figures by the authors. Its bibli- 

 ography must be revised entirely. 



Blologij. — The colonies are a deep purple or a beautiful red violet. 

 In life they are always covered with dirt and never have the beau- 

 tiful aspect of the published figures. Their numerous spines retain 

 a large number of small particles of all kinds, calcareous, argilla- 

 ceous, and sandy, with small foraminifera developed among them. 

 The operculum itself is not free. The chitinous sponges erect their 

 first filaments here which seems to indicate a much restrained mo- 

 bility of the spines. Also the immediate determination is absolutely 

 impossible, for an army of small dirty sticks only is visible. Wash- 

 ing in Javelle water is absolutely necessary in order to discover the 

 other characters, whereupon the cells appear with an incomparable 

 richness of ornamentation, the usual indication of calm waters. 



The action of the avicularium is absolutely incomprehensible and 

 their inversion on the ovicells does not give us any information. 



Occurrence. — Galapagos Islands, D. 2815. 



Cotypes.—C&t. No. 8250, U.S.N.M. 



Family MAMILLOPORIDAE Canu and Bassler, 1927 

 Genus MAMILLOPORA Smitt, 1873 



MAMILLOPORA CUPULA Smitt, 1873 



"We have observed 15 very small dead colonies. We have studied 

 equally small colonies from the Gulf of Mexico, but they are much 



