96 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



well chitinized, with a pair of strong sclerites which reach forward from 

 the heavy cardelles > it is complete on the proximal border, but is attached 

 to the ectocyst from which it is easily separated; in dried or alcoholic 

 specimens the contraction usually detaches it from the ectocyst. There 

 is a row of uniporous septulae in the lateral and distal walls. No ovicells. 



Osburn described the species from Curacao Island in the southern 

 Caribbean Sea and in the following year, before the description of antillea 

 was available, Canu and Bassler named it pumicosa from southern 

 Florida. It is widely distributed in the West Indian region. Pacific coast 

 specimens appear to agree in every particular. 



Albatross Stations: D.2824 and D.2825, Gulf of California. 



Genus ANEXECHONA new genus 



Zoarium encrusting, often multilaminar, rarely with erect, flat 

 branches. Frontal wall a pericyst, with large funnel-shaped pores, above 

 the frontal membrane or ectocyst which covers the whole opesia; peri- 

 stome wanting, the operculum on a level with the zoarial surface; side 

 walls with multiporous, the distal wall with uniporous septulae. Avicu- 

 laria large, vicarious, occupying a place in the zooecial series. No spines 

 nor tubercles. No ooecia. Genotype, Anexechona ancorata Osburn, new 

 species. 



This genus is evidently related to Exechonella by the manner of form- 

 ing the porous pericyst, which grows inward from all sides without any 

 evidence of spines. It differs in the absence of a salient peristome, in the 

 nature of the operculum, and in the presence of large vicarious avicularia. 

 Since Canu and Bassler selected the name Exechonella because of the 

 raised peristome, I am adopting Anexechona, not salient, for the present 

 genus. 



•^ Anexechona ancorata new species 

 Plate 11, fig. 1 



The zoarium encrusts shells, stones and occasionally algae; often 

 several layers in thickness, rarely erect and bilaminate, back to back; 

 dorsal surface smooth ; frontal surface flat and smooth ; light yellow to 

 brownish in color. 



Zooecia distinct, but the interzooecial grooves very shallow; the 

 brown opercula and avicularian mandibles standing out prominently. 

 The zooecia are large, 0.65 to 0.80 mm long by 0.40 to 0.50 mm wide ; 

 the frontal nearly flat, consisting of a smooth pericyst with large in- 

 fundibular pores evenly arranged. The region about the aperture is 



