16 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



oval opesia occupies about half of the frontal surface. No avicularia. 

 Ovicell hyperstomial, borne on a somewhat reduced zooecium. Genotype, 

 Sertularia chelate Linnaeus, 1758. 



Scruparia ambigua (d'Orbigny), 1841 

 Plate 1, fig. 5 

 Eucratea ambigua A' Orhigny, 1841 : pi. 3, figs. 13-17; 1847:11. 

 Eucratea chclata, Robertson, 1905 :248. 

 Eucratea chelata, O'Donoghue, 1926:42. 

 Scruparia chelata, Hastings, 1930:702. 

 Scruparia ambigua, Hastings, 1941 :470. 



Zoarium creeping, with erect branches ; the creeping base consisting 

 of zooecia (no stolon). The proximal end of the zooecium is tubular and 

 gradually expanding; the opesia occupying one-third to one-half of the 

 zooecial length and nearly parallel to the dorsal surface. Budding takes 

 place either dorsally at the distal end or frontally immediately proximal 

 to the opesia, the latter giving rise to erect branches. 



The ovicell is hyperstomial, the fertile zooecium only slightly re- 

 duced. 



This species has been much confused with S. chelata (Linnaeus) and 

 Dr. Anna B. Hastings has pointed out the differences (1941). In chelata 

 stolons are present, the opesia is set at a rather sharp angle to the dorsal 

 wall, the zooecia are shorter and not so slender, and the fertile zooecia 

 are more modified, with a much reduced opesia. 



D'Orbigny described the species from the Falkland Islands (lies 

 Malouines), and Hastings shows that it has a very wide distribution 

 around the world. Robertson recorded it as Eucratea chelata from the 

 coast of southern California; Hastings listed it from the Galapagos Is- 

 lands; O'Donoghue found it at Union Bay, Vancouver Island region, 

 which is the northernmost record for the Pacific coast. 



In the Hancock collections it is a common form about the islands of? 

 southern California and along the coast of the mainland, from low tide 

 mark down to 150 fathoms. 



Genus BRETTIA Dyster, 1858 

 The zoarium is erect and branching, the branches usually arising in 

 pairs near the distal end on the dorsal side of a zooecium and facing in 

 the same direction. The zooecia are uniserial, subtubular and elongate, 

 with the opesia subterminal. In the genotype (5. pellucida Dyster) there 

 are small spines, but this is not a constant character in the genus. No 

 ovicells nor avicularia. 



