102 PEOCEEDINGS OP THE NATIONAL MUSEUM VOL.72 



several of our specimens it changes its position and becomes trans- 

 verse. 



The microme trie measurements are quite inconstant and vary from 

 single to double, but the general structure remains always the same. 

 The transverse section indicates that the zooecia of the superposed 

 lamellae arranged in rows and not in quincunx. 



Biology. — This species forms large, free colonies, but the lamellae 

 are superposed only on one side. It is incrusted by small species 

 of bryozoa. It appears to prefer the great depths. The dredgings 

 of the Albatross showed it to have been in reproduction from January 

 to May. 



« Occurrence. — ATbatross Station D. 2167, off Havana, Cuba; 23° 10' 

 40" N; 82° 20' 30'' W.; 201 fms.; coral. 

 Albatross Station D. 2319, north of Cuba; 23° 10' 



37" N.; 82° 20' 06" W; 143 fms.; gray coral. 

 Albatross Station D. 2330, north of Cuba; 23° 10' 



48" N.; 82° 19' 15" W; 121 fms.; gray coral. 

 Pleistocene: Panama Canal Zone. 

 Coty pes. —Csit. Nos. 7505, 7506, U.S.N.M. 



GEMELLIPORIDRA ACULEATA, new species 



Plate 9, Figure 5: text Figure 17 f, g 



Description. — The zoarium encrusts shells. The zooecia are dis- 

 tinct, separated by a deep furrow, elongated, elliptical, or subrec- 

 tangular on the zoarial margin; the frontal is convex, covered by a 

 granular tremocyst with very small pores. The aperture is orbicular 

 or somewhat transverse; the cardelles are small; the peristome is a 

 little salient, granular, and formed by the tremocyst. The ovicell 

 is globular, salient, closed by the operculum. Sporadically there 

 are avicularian zooeciules bearing a long slender mandible in the 

 form of a needle; they are always primoserial. 



7,^ ^ A ^ |?ta = 0.12-0.15 mm. 



Measurements. — Aperturei , ^ ^ ^ 



Ua = 0.15 mm. 



r7 . \Lz = 0.G5 mm. 

 Zooecia^, . .^ 



ife = 0.40 mm. 



ry . 1 \Lz = Q.55 mm. 

 Zooecmlesi, ^ „_ 



us = 0.25 mm. 



Affinities. — This species is very well characterized by its avicularian 

 zooeciules which are always primoserial. We have found two kinds 

 of opercula; the more transverse belong apparently to the ovicell ed 

 zooecia; the others are surrounded by a marginal band on which the 

 opercular muscles are laterally inserted. Our two specimens were 

 dredged alive. 



Occurrence. — Fowey Light, 15 miles south of Miami, Fla.; 40 fms. 



Holotype.—C&t. No. 7507, U.S.N.M. 



