48 BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 



Genus CAULORAMPHUS Norman, 1903. 



(For description, see Bulletin 106, U. S. National Museum, p. 174.) 



CAULORAMPHUS POROSUS, new species. 



Plate 33, fig. 17. 



Description. — The zoarium incrusts shells and bryozoa. The zooecia are large, 



distinct, separated bj' a deep furrow, irregularly elliptical; the mural rim is thin 



flat, finely striated, very little enlarged at the base; the opesium is large of the same 



form as the zooecium. Between the mural rims in the separating furrow there are 



numerous pores (8 to 10) which are bases of pedunculate and articulate avicularia. 



^ „ . f?io = 0.40-0.44 mm. „ . [i2 = 0.60mm. 



Measurements. — Opesia , _ „„ _ „„ Zooecia , _ .. _ ._ 



^ 1 ?o = 0.28-0.32 mm. 1 42=0.44-0.50 mm. 



Affinities. — It should be remarked that the pores are not arranged on the mural 

 rim where the termen is sharp. There are therefore no hollow spines; but they form 

 the base, the place of attachment of pedunculate avicularia which surmount them. 

 It is therefore in the genus Cauloramphus that this remarkable species must be 

 classified. 



The avicularia being organs of oxygenation we suppose that this species must 

 live in absolutely calm waters little rich in diatoms. The incessant agitation of the 

 mandibles appears to be intended to renew the impure water and to thus carry 

 oxygen and nourishment. 



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



Holotype.—C&t. No. 68464, U.S.N.M. 



CAULORAMPHUS TRUNGULARIS, new species. 



Plate 33, figs. 14-16. 



Description. — The zoarium incrusts shells and bryozoa. The zooecia are 



distinct, separated by a wide and deep furrow, elongate, elliptical, with a very short 



proximal gynmocyst; the mural rim is wide, rounded, salient and bears two small 



distal and eight large areal hollow spines placed in the distal half of the zooecium; 



the opesium is elliptical or oval according to the form of the zooecium. The ovicell 



is hyperstomial, globular, ornamented by a semicircular area. In the separating 



furrow with each zooecium there is a small triangular pore which is the base of the 



articulation of a pedunculate and articulate avicularium. 



■,/■ ../-»• 1^0 = 0.30-0.34 mm. _ . [1,2 = 0.48-0.52 mm 



Measurements. — Opesia , „ , o r^ oo Zooecia, ^^ 



^ Uo = 0.18-0.22 mm. 1 Zz = 0.32-0.40 mm. 



Affinities. — The presence of the small exterior avicularium at the line of the 

 spines seems to indicate Memhranipora {Cauloramphus) corniculifera Hincks, 1882, 

 from the Queen Charlotte Islands. It differs from it in a smaller number of spines 

 (less than 18) and in the very different arrangement of distal and areal spines. It 

 differs from Cauloramphus spiniferum Johnston in the larger micrometric measure- 

 ments (Z2>0.43 mm.), in the presence of less than 12 spines and in the triangular 

 form of the pore of the pedunculate avicularium. The tAvo species are evidently 

 very close. 



The ancestrular zooecia are smaller than the others. The ancestrula is oval, 

 garnished by 12 spines; it engenders three large and three small zooecia. 



