644 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



of Mexico; the most southern record is Hancock Station 460-35, at 

 Playa Blanca, Costa Rica. The bathymetric range is from low tide to 

 about 100 fms. 



Diaperoecia floridana Osburn, 1940 

 Plate 67, fig. 3 



Idmonea Milneana, Smitt, 1872:8 {non d'Orbigny). 



Diaperoecia radicata, Canu and Bassler, 1928:160 (no;z Kirkpatrick) . 



Diaperoecia floridana Osburn, 1940:331; 1947:5. 



"? Diaperoecia rugosa Osburn, 1940:332. 



The zoarium is erect or sprawling, idmoneiform, irregularly branched, 

 the branches slender, 0.60 to 1.0 mm in width, sometimes anastomosing; 

 both dorsal and ventral sides more or less wrinkled ; strong unjointed 

 radicles developed on the dorsal side. The tubules are elongate ; in 

 younger branches the outlines are definite but the lines disappear with 

 age; 4 or 5 to 6 or 7 tubules make up the width of a branch; the 

 peristomes are curved, sometimes more than 1.0 mm long but usually 

 about 0.40 mm, varying in diameter from 0.16 to 0.20 mm, the aperture 

 varying from 0.13 to 0.17 mm; in older specimens transversely wrinkled 

 nearly to the tips, perforated at the base. 



The ovicell is elongate, usually located near the end of a branch and 

 may extend up both branches at a bifurcation, usually surrounding one 

 or more peristomes ; but smaller ones may fail to enclose any. The 

 ooeciostome is independent of the peristomes, usually situated near the 

 middle of the ovicell; but when this is branched it is located near the 

 base of the fork. It has the same width as the peristomes, usually bent 

 sharply toward the base but in the forked ovicells it is more or less 

 erect. The tip of the ooeciostome in any case, when fully developed, is 

 broadly flared, irregularly elliptical, and measures from 0.20 to 0.35 

 mm wide by about 0.16 mm in the shorter dimension. 



Pacific specimens have been compared with those from the Atlantic 

 and seem to show no essential differences. Also I am inclined to place 

 D. rugosa in synonymy, since in our abundant material there is much 

 variation in the size of the peristomes, the amount of striation, and the 

 form and position of the ooeciostome. 



Described from off Beaufort, North Carolina, and recorded also by 

 Osburn from the southern shore of Porto Rico and from several localities 

 on the southern shore of the Caribbean Sea; by Smitt (Idmonea milne- 

 ana) from Florida, and by Canu and Bassler (D. radicata) from the 

 Gulf of Mexico and the Straits of Florida. 



