ART. 13 BRYOZOAN FAUNA CANU AND BASSLER 31 



cylindric, slightly compressed. The two faces of the colony are 

 covered by salient vibices outlining polygonal spaces in each of 

 which there is an elliptical avicularium and sporadically, radial 

 sculpture. The zooecia are arranged on the edge of the branch in 

 the fenestrae and in a single row; they are little distinct, separated 

 by a salient thread, little elongated, wide; the frontal bears salient 

 longitudinal nervures. The apertura is oblique, located at the bot- 

 tom of a parietal peristomie and hidden by a salient, more or less 

 sinuous mucron. Two small lateral avicularia are placed at the 

 extremities of the transverse axis of each zooecium. 



Biology. — ^^^e have found only small dead and incomplete frag- 

 ments of this strange species and therefore are unable to make a 

 serious study. The function of the vibices in the Reteporidae being 

 unknown, we are not able to explain their presence on the two faces 

 of the colony. One must admire the really prodigious work ac- 

 complished by the two simple rows of cells of each branch, their 

 length being only 0.70 mm. Their architectural ability must be 

 accompanied by an enormous voracity, for which reason there is 

 a large number of avicularia. The function of the latter must be 

 to chase the plancton into the fenestrae, where it is easily snapped 

 up b}^ the tentacles. 



Occurrence. — Galapagos Islands, D. 2813 and 3408. 



n oJotype. —C?it. Nos. 8502, 8503, U.S.N.M. 



DIPLONOTOS STRIATUM, new species 

 Plate 10, Figures 1-3 



Description. — The zoarium is free, ramified, with cylindrical or 

 somewhat compressed pinnules. The latter beai' two rows of cells 

 placed opposite each other and arranged laterally. The branches 

 are very finely striated by delicate and incomplete sulci at the bot- 

 tom of which are minute scattered vacuoles. Salient vibices occur 

 in the wider portions, which give the branches a vague articulated 

 aspect. Between two vibices there are at least three cells. The zo- 

 arial epitheca is very thick and formed of numerous cylindrical 

 lamellae. The zooecia are indistinct, elongated, oriented laterally 

 toward the adjacent pinnules. The aperture is broad, very little 

 elongated, and bears a small proximally rounded sinus. No per- 

 istome. Oviceil unknown. Some of the lateral vacuoles are trans- 

 formed into small avicularia. 



Measurements. — 



A«= 0.22-0.24 mm. |Z3= 1.00-1.60 mm. 



Apertura ^«= 0.20-0.22 mm. Zooecia j^^_ ^ 



Diameter of the large branches, 2 mm. 



