NORTH AMERICAN LATER TERTIARY AND QUATERNARY BRYOZOA. 47 



RAMPHONOTUS MULTISPINATUS, new species. 



Plate 34, fig. 4. 



Description. — The zoarium incrusts shells. The zooecia are oval or elliptical, 



elongated, distinct; separated by a deep furrow; the mural rim is wide, salient, 



round, and bears four small distal spines, two large hoUow spines at the level of 



the condyles, and a variable number of areal spines; the opesium is anterior, oval, 



trifoliated. On the gymnocyst there is a large avicularium. 



,, , r^ ■ \h.o = 0.24tinm. „ . (is = 0.40-0.50 mm. 



Measurements. — Opesia , r>i^nio Zooecia, rvoorv.n 



^ 1 (0 = 0.16-0.18 nam. I te = 0.28-0.40 mm. 



Affinities. — The two large spines are fixed at the level of the condyles which 

 narrow the opesium and which serve for the articulation of the opercular valve. 



This species differs from RampJionotus asperus in its spines, which are more 

 numerous and of two Idnds. 



Occurrence. — Pleistocene: Santa Barbara, California (rare). 



Holotype.— Cat. No. 68462, U.S.N.M. 



RAMPHONOTUS AGELLUS Ulricb and Bassler, 1904. 



Plate 13, figs. 8-10. 



1904. Amphiblestrum agellus Ulrich and Bassler, Bryozoa, Maryland, Geological Survey, Miocene, 

 p. 414, pi. 112, figs. 7a, 76; pi. 118, fig. 14. 



Description. — The zoarium incrusts shells. The zooecia are distinct, separated 

 by a deep furrow, ovoid, much enlarged at their base; the mural rim is thin and 

 sharp; the cryptocyst is short, oblique, concave. The opesium is transverse, tri- 

 foliate, much narrowed at the level of two large spines and of the hinge of the oper- 

 cular valve. The oviceU is quite salient, globular, smooth, formed of two cal- 

 careous lamellae the superior one of which is incomplete and limits a small semi- 

 lunar frontal area. The gymnocyst bears a large very salienf oblique avicularium 

 with its beak turned toward the base. 



,, . /-v • (Ao = 0.20mm. „ . [2.2 = 0.46 mm. 



Measurements. — Opesia , . „_ . _ , Zooecia , nor, r.Ar 



^ I io = 0.22-0.24 mm. | te = 0.30-0.46 mm. 



Variations. — The original type of the species is incomplete and formed of 



ancestrular zooecia, which in this genus are always much smaller than the normal 



zooecia. Other specimens found at the same horizon in Virginia appear to represent 



the true form of the species. The avicularium is triangular and very salient. On 



account of its oblique arrangement it is very fragile and is not well preserved in 



fossilization. The opesium is elongated in the ancestrular zooecia but transverse 



in the other. 



Affinities. — This species differs from Ramphonotus minax Busk, 1864, in its 

 trifoliate opesium and in its avicularium oriented in the zooecial axes. It differs 

 from R. asperus in the presence of two large spines instead of six and in its avicularium 

 not arranged transversely. The worn or broken forms of this species are very 

 difficult to distinguish. 



Occurrence. — Miocene (St. Mary's formation) : Cove Point, Maryland (rare) ; 

 Bowler's wharf, 18 miles above Urbana, Middlesex County, Virginia (rare).' 



Plesiotype—C&t. No. 68463, U.S.N.M. 



