340 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Hippodiplosia pertusa (Esper), 1796 

 Plate 40, figs. 5-8 



Cellepora pertusa Esper, 1796:149. 

 Lepralia pertusa, Hincks, 1880:305. 

 Hippodiplosia pertusa, Hastings, 1930:724. 

 Hippodiplosia pertusa, Osburn, 1933 :41. 



Zoarium encrusting, often covering considerable areas on shells, etc. 

 Zooecia moderately large, 0.60 to 0.75 mm long by 0.35 to 0.45 mm 

 wide, distinct with deep grooves, the front considerably inflated, a 

 tremocyst with numerous large pores. The aperture is moderately large, 

 0.16 to 0.18 mm in each dimension, nearly round, the proximal border 

 a wide arc behind the strong denticles. The peristome is low and thin, 

 not covered by the tremocyst. Proximal to the aperture an umbo is 

 often present and in our Cahfornia specimens it is exceptionally high 

 and strong, ending in a point. No spines, no avicularia. 



The ovicell is large, prominent, irregularly perforated, closed by the 

 operculum. 



It is a very widely distributed species and has been recorded in the 

 Eastern Pacific by Hincks from Mazatlan, Mexico, and by Hastings 

 from Gorgona, Colombia, and from the Galapagos Islands. 



Hancock Stations: 1232-41, San Pedro, shore; 1283-41, Santa Rosa 

 Island, 23 fms; and 1295-41 and 1666-49, Santa Cruz Island, 17 fms, 

 southern California. 



Hippodiplosia reticulato-punctata (Hincks), 1877 

 Plate 40, fig. 3 



Lepralia reticulato-punctata Hincks, 1877:103. 

 Escharella porifera form edentata Smitt, 1867 :9. 

 Schizoporella reticulato-punctata, Nordgaard, 1918:66 

 Hippodiplosia reticulato-punctata, Osburn, 1933:41. 



Zoarium encrusting. Zooecia moderately large, 0.60 to 0.70 mm long 

 by 0.45 to 0.60 mm wide, broad and little inflated, more or less distinct. 

 The frontal is a tremocyst with very large pores which increase in size 

 outward so that the surface of old zooecia looks like a network. The 

 tremocyst does not involve the proximal border of the aperture but 

 leaves a small v-shaped area which is usually occupied by a suboral 

 avicularium. The peristome is thin, a little elevated on the sides but 

 wanting on the proximal border, no oral spines. The aperture is broader 

 than long, 0.20 to 0.24 mm wide by 0.18 to 0.20 mm long, regularly 

 rounded back to the cardelles, behind which it is broadly arcuate. A 



