706 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL, 14 



are in radiating uniserial rows, high next to the central area (often 1.0 

 mm or more in height), and sloping gradually to the edge, which is 

 surrounded by a moderately broad basal lamina. Shorter rays appear 

 between the main ones toward the margin. The tubules are connate to 

 the tips, and slightly compressed, the apertures about 0.08 mm in di- 

 ameter, the tips prolonged into points on the central side and often also 

 on the outer side. The cancelli are extremely variable in size and form, 

 producing an irregular network; the largest are more than twice the 

 width of the zooecial apertures and the smallest are even less than the 

 apertural width. There is no evidence of closure of the cancelli by an 

 "iris" diaphragm, but instead they often become closed by a thin calcified 

 membrane with numerous small pores like that which covers the ovicell, 

 and this is true for some of the cancelli near the outer border beyond 

 the brood-chambers. 'Tinhead" spicules are present within the apertures 

 of the cancelli, often in nearly every one but sometimes more rare; 

 usually they are present slightly above the closing membrane, and it may 

 be that these cancelli are regenerated. Between the rays there are one 

 or two rows of cancelli. In old and more heavily calcified specimens the 

 walls of the cancelli are thicker but not closed by an iris-like diaphragm. 



The brood-chambers occupy the central area but often extend for a 

 considerable distance into the interradial spaces; the roof consists of a 

 thin calcified and perforated membrane and soon becomes covered with 

 a secondary layer of cancelli. The ooeciostome is excentric in position, 

 the tube short, the orifice round and about as large as that of a zooecial 

 tube, the lip round or elliptical and slightly flared. 



Harmer, 1915 :155, includes L. holdsworthi under L. novae-zelandiae ; 

 Waters, 1918:36, reverses this and includes novae-zelandiae under 

 holdsworthi, though the former has page priority in publication. From 

 Busk's figures of these species, 1875, plate 30, figs. 2 and 4, there appear 

 differences in the height of the peristomes, the mode of closure of the 

 cancelli, and especially in the size of the central area, sufficient to war- 

 rant their separation. L. holdsworthi has the appearance of a Discopo- 

 rella. The L. holdsworthi of Canu and Bassler, 1929, plate 88, fig. 11, 

 has short biserial rays and probably should go elsewhere. 



The species was described from New Zealand and later recorded from 

 Australia, Ceylon and Japan. While it has not been listed from the 

 American Pacific, our specimens conform so closely to the descriptions 

 and illustrations of Busk and Harmer that they appear to belong to this 

 species. Also I believe that the L. radiata of Robertson from southern 

 California belongs here, and possibly that of O'Donoghue (without 

 description) from British Columbia. 



