92 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 16 



Genus PARACYATHUS Milne Edwards and Haime 



Paracyathus Milne Edwards and Haime (1848), Ann. Sci. Nat., ser. 

 3, vol. 9, pp. 318-319. 

 Genotype : Paracyathus stokesii Milne Edwards and Haime. 



Paracyathus humilis Verrill 

 Plate 12, figs. 54a, b 



Paracyathus humilis Verrill (1870), Trans. Conn. Acad. Arts Sci., vol. 

 1, p. 538. 



The specimens at hand have 4 cycles of septa with some of the fifth 

 cycle present. Pali terete, tall, slender, "most of them with irregular sides 

 from which are developed small rough lobes, projecting in various direc- 

 tions" (Verrill, 1870). Occasionally, the pali before the third cycle are 

 divided. The costae and their interspaces are somewhat irregular in 

 development, probably due to environmental circumstances. The costae 

 are wide, with large and small granules, the large ones composed of 

 fused smaller ones. 



Verrill's material came from the Pearl Islands. 



Hypotype: Cat. no. 54.1 (Sta. 137-34). 



Material examined: Sta. 137-34 (1). 



Distribution: Sulphur Bay, Clarion Island, 57 fms. 



Paracyathus stearnsii Verrill 

 Plate 13, figs. 55a-e 



Paracyathus Stearnsii Verrill (1869), Proc. Boston Soc. Nat. Hist., vol. 



12, p. 393; (1870), Trans. Conn. Acad. Arts Sci., vol. 1, pp. 



537-538. 

 Paracyathus pedroensis Vaughan (1903), Mem. Calif. Acad. Sci., vol. 



3, pp. 88-90, pi. 3, figs. 1, la; Durham (1947), Geol. Soc. Am., 



Mem. 20, p. 35, pi. 3, figs. 3, 4. 

 Paracyathus stearnsii Verrill, Durham (1947), Geol. Soc. Am., Mem. 



20, p. 35, pi. 2, figs. 1, 2, 5, 6. 

 Over 400 specimens from 89 stations are present in the Allan Han- 

 cock Foundation collections. This species is extremely variable, with 

 calices usually oval but occasionally very elongate-elliptical. 



Paracyathus pedroensis Vaughan was based on specimens with un- 

 divided pali, but intergrades show that the pali of these forms, when the 

 corallum attains a larger size, begin to divide, with the later cycles 

 dividing sooner. Occasionally, specimens may reach a fairly large size 

 before their pali divide but specimens in association with these are typical 

 P. stearnsii. 



