88 california academy of sciences. 



Differential Characters of the Three Calipornian Species of Caryophyllia. 



Septa in four cycles ( form cornute; twelve more prominent costs ) C. pedroensis 



i form short, inversely subconical, costae ) 



\ equal near the calice, alternating in size / C. arnoldi 



( near base ) 



Septa in four com- 1 J 



plete cycles, many 1 form subflabellate, costas excepting near the f ^ caiiforviica 

 members of the fifth 1 calicular margin indistinct ( ' 



present 



As the descriptions and the above table show, for the differentiation of the spe- 

 cies, especial stress is laid npon the number of the septa, the form, and the costal charac- 

 ters. Although each of the three species is based on a single sjjecimen, the autlior does 

 not believe it possible for intergradation to occui' within the horizons from which 

 they were collected. C. pedroensis and C. arnoldi appear to belong in the same 

 group (section) of tiie genus; but C. califoriiica presents great and striking differ- 

 ences from each of the preceding. 



Genus Paracyathus Milne- Edivards S Haime. 



Verrill has described three species of Paracyathus from the west coast of 

 North America, viz.: Paracyathus caltha,^ Paracyathus siearnsi^' and Paracyathus 

 humilis.^ The first two species mentioned are from Monterey, California; the last 

 mentioned is from the Pearl Islands. 



Expressed in tabular form the differences between these three species are: — 



\ Cost.'B distinct only at edge of calice, be- 1 



„ I, K ■ ( low represented by rows of granules; axes of ( P. caltha 

 Corallum 5 m or ^^^.^^ ^^ j^^ 3., ^^ 



more m height; nve J ' ' 



complete cycles of j gg^brous, subequal costiB, distinct to base, | 



" I near base every fourth or sixth costa more ; P. stearnsi 



[ prominent; axes of calice, .72 in. /.50 iu ) 



Corallum only .2 in. 1 ^ , , 1, . i- 1 ■ ) 



. , ■ X.. , 1 CostiB feeble, except near calicular margin. ( „ , ... 



in height; four com- Diameter of circular calice, .22 in ( ^- A"""-!" 



plete cycles of septa. ( ' ) 



• 



According to the diagnostic characters given by Verrill, these three species 

 are very distinct. 



4. Paracyathus pedroensis Vaughan, sp. nov. 



Plate III, Figs. 1 and In. 



Corallum subturbinate in shape, base damaged, apparently not especially expanded; trans- 

 verse outline of calice elliptical, slightly deformed. 



Costfe not prominent, but distinct from the calicular margin to the base, subequal, some- 

 times every third or every fifth may be slightly more ])rominent than tho.se intervening, the edges 

 usually flattisl), sometimes slightly crested. Bottoms of the intercostal furrows usually llattish; 

 granulations crowded on the costee, and present iu the intercostal furrows also. 



> Proc. Boat. Soc. Nat. Hint., Vol. XII, 1869, p. 394: Trans. Conn. Acad. 8ci., Vol. 1, 1870, p. 637, PI. IX, figs. 9, 9a. 



' Proc. Bout. Soc. Nal. Hist.. Vol. XH, 1869. p. 393; Trans. Conn. Acad. Scl.. Vol. I, 1870, p. 337. 



' Trans. Conn. Acad. Scl.. Vol. I. 1870, p. 638. 



* These decimals of an inch can be computed into mllliracters by reckoning .1 inch = 2.5 mm. 



