51 



BATOCKINUS COl'IOSUS, II. Sp. 



Platfi V, Fig- 5, tizj/goits- rieir ofra/7/.v and raiiJt: Fig. (>, op/tosite 

 Ttew of .same, fipei'i men s/ig'Jitli/ compressed. 



Body rather abovi> inediiuii size. Calyx l)roa(lly truncated at 

 the base, one-half wider than high, arm opeuings directed twenty 

 degrees above a horizontal line; plates thick, convex; sutures dis- 

 tinct; surface granular 



Basals short, thick, and forming a low, hexagonal cup, four 

 times as wide as liigh, with a round hemispherical depression 

 radiately furrowed for the attachment of the column. The thick- 

 ness of the plates outside the column is about equal to half its 

 diameter. They stand upright and are beveled toward the sutures. 

 First radials the largest plates in the calyx, twice as wide as 

 high, unequal in size, three hexagonal, two heptagoual, and each 

 one bears a highly convex, transverse, obtusely angular ridge. 

 Second radials small, quadrangular, and more than twice as wide 

 as long. Third radials small, pentagonal, rather wider than the 

 second, about, twice as wide as high, axillary, and bear upon each 

 upper sloping side the secondary radials. There are two secondary 

 radials in each series except in one opposite the azygous area 

 where there are four secondary radials uf)on each side of the third 

 radial. The first secondary radials in the four series are small 

 and quadrangular. Tlie second secondary radials in the four 

 series are rather large, wide plates, bearing a transverse ridge, 

 axillary, and support upon each upper sloping side three tertiary 

 radials. There are, therefore, four arms, in each of four series, 

 and two arms in the ray opposite the azygous side, or eigliteen 

 arm openings to the vault. 



There is only a single regular interradial in each area, one has 

 nine sides, another ten, another eleven and the other twelve sides. 

 Each one bears a prominent central node. There are four plates 

 in the azygous area; the first one is larger than a regular inter- 

 radial, is in line with the first radials, though somewhat higher, 

 and bears a transverse convex ridge, it is followed by three plates, 

 each about the size of a regular interradial and each bearing a 

 central node. 



The vault is cjuite as large as the calyx, most ventricose on one 

 side, and bears a subcentral [jroljoseis. It is covered by large, 

 nodose, polygonal plates. There are two pores penetrating the 

 vault between each of the radial series. 



