536 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



Variations. — We group under the name of Diaperoecia rosea a num- 

 ber of specimens coming from different localities, but we are not posi- 

 tively certain that they belong to the same species. The specimens 

 from Sibutu (China Sea) especially, appear to us somewhat diver- 

 gent in their ensemble. Moreover the incrusting specimen from 

 Sulade, in spite of the identity of the micrometric measurements, is 

 perhaps a Tubulipora; its ovicell is incomplete. 



As Harmer, 1915, has already demonstrated, the determination of 

 Cyclostomata from different localities is always difficult when the 

 material is not very abundant. 

 Occurrence. — 



D. 5137. Jolo Light, Jolo; 6° 04' 25" N.; 120° 58' 30" E.; 20 



fathoms; S. Sh. 

 D. 5147. Sulade Island, Sulu Archipelago; 5° 41' 40" N.; 120° 



47' 10" E.; 21 fathoms; co. S. Sh. 

 D. 5574. Simaluc Island, north of Tawi Tawi; 5° 30' 45" N.; 



120° 07' 57" E.; 340 fathoms. 

 D. 5580. Sibutu Island, Darvel Bay, Borneo; 4° 52' 45" N.; 

 119° 06' 45" E.; 162 fathoms; br. S., Co. 

 Cotypes — Cat. Nos. 8360-8363, U.S.N.M. 



DIAPEROECIA TRANSVERSALIS, new species 



Plate 81, figs. 1, 2 



Description. — The zoarium is free and unilamellar or encrusting 

 bryozoa; the branches are long and sinuous. The tubes are little 

 distinct, wrinkled transversely, convex; the peristomies are long, very 

 erect, terminated by a thin peristome; they are arranged in fascicles 

 of 2 to 4 tubes and disposed transversely. The ovicell is large, ellip- 

 tical, pierced by a dozen isolated peristomies; the oeciostome is 

 small, transverse, orthogonal, sublateral. 



Measurements. — Diameter of peristome, 0.24-0.26 mm.; diameter 

 of oeciostome, 0.09; width of branches, 1.00; and distance of fascicles 

 (without peristome), 0.40-0.60. 



Affinities. — The fascicles occupy all the zoarial width; when they 

 are formed of two tubes they are arranged in lateral opposite groups 

 as in Idmonea. 



A remarkable characteristic of this species is that the tubes which 

 traverse the ovicell are isolated and not grouped in fascicles. If our 

 ovicelled specimen had not borne some transverse facscicles we would 

 not have been able to refer it to the present species. The zoarial 

 aspect is remarkable. It is neither a Tubigerina, a Tubulipora, nor 

 an Idmonea although presenting a union of these three ancient genera. 

 In the old zoarial classification a special genus for this species would 

 have been necessary. This species shows moreover that the grouping 

 of tubes in fascicles is not a characteristic peculiar to Tubulipora and 



