NO. 1 OSB URN : EASTERN PACIFIC BRYOZOA CHEILOSTOMATA 31 



their description, but a specimen from Cape Blanco, West Africa, the 

 type locality, received through the kindness of Dr. Anna B. Hastings of 

 the British Museum, shows a very few delicate, almost transparent 

 spinules. 



The Hancock Expeditions recovered this species from off Guaymas 

 (Station 1092-40) and Tepoca Bay (Station 1078-40), Sonora, Mexico; 

 Santa Maria Bay, Lower California (Station 1031) ; Cocos Bay, Costa 

 Rica (Station 116-33), and La Plata Islands, Ecuador (Station 212-34). 

 Dr. Howard R. Hill of the Los Angeles Museum has presented the writer 

 with a specimen from San Felipe, western Mexico. It is therefore widely 

 distributed in warm waters along the Pacific coast from northern Mexico 

 to Ecuador. Depth 2 to 45 fathoms. 



>- Conopeum reticulum (Linnaeus), 1767 

 Plate 2, fig. 11 



Millepora reticulum Linnaeus, 1767:1284. 

 Membraniporalacroixiij Robertson, 1908:261, (?part). 

 Membranipora lacroixii var. triangulata, O'Donoghue, 1923:25. 

 Conopeum reticulum, Harmer, 1926:211, synonymy and discussion. 

 Conopeum reticulum, Osburn, 1940 :350-352, discussion. 



Zoarium encrusting on various substrata. Zooecia of moderate size, 

 usually about twice as long as the width but occasionally short and wide, 

 usually ranging in length between 0.40 and 0.50 mm. There is a short 

 gymnocyst (often vestigial), which typically bears a pair of triangular 

 areas in the proximal corners. These triangular structures are at first open 

 with a membranous covering, but later they often become closed and 

 knob-like, or they may be fused into a single knob, often they are wanting, 

 sometimes over considerable areas of a colony. They may be readily con- 

 fused with the minute or vestigial avicularia of some species of Antropora 

 but they are merely surface structures on the basal gymnocyst and are 

 probably homologous with the basal tubercles of some species of Mem- 

 branipora. 



The opesia is elliptical, oval or rounded. The walls are rather heavily 

 calcified and the descending cryptocyst coarsely granular, sometimes with 

 conical points projecting laterally inward. Ovicells are wanting. Small 

 avicularia have been mentioned by some authors, but I have never been 

 able to find them in either Atlantic or Pacific specimens and I am in- 

 clined to believe the authors were mistaken or had some other species. 



In the literature up to 1926 this species was generally confused with 

 lacroixi Audouin, and most of the references are under that specific name. 



