REPORT ON THE RAUIOLARIA. 373 



liores 0-008, bars 0-004. Length of the pular tubes dfJ?, basal breadth 0-04; pores 0-003, 

 l>ars 0-002. 



Habitat. — North Paeific, Station 253, deptli 3125 fathonip. 



2. Cannaiilsciis (-OiipJnci/Jiudru.'^, n. sp. 



Cortical shell thick walled, rough, with subregular, circular jjores, twice to four times as broad 

 as the bars ; six to seven on the half meridian, ten to tweh'e on the half equator- of each 

 chamber. I'olar tubes cylindrical, on the distal end open (broken off?) nearly as long as 

 the main axis, somewhat narrower than the spherical medullary shell. Pores of the tubes much 

 smaller than those of the chambers. 



Dimensions. — Main axis (witliout tubes) O'lT, greatest breadth 0-12; pores O'OOG to 0-012, 

 bars 0-003. Length of the polar tubes O'lo, breadth of them 0-03 ; pores 0-003, bars 0-002. 



Habitat. — Paciiic, central area, Station 268, 2900 fathoms ; the same form occurs fossil in the 

 locks of Barbados. 



Genus 1(32. Cannart'tdiuni} n. wu. 



Definition. — Cyphinida with simple cortical shell and double medullary shell, 

 with two hollow fenestrated polar tubes, opposite on Itotli |)oles of the main axis. 



The genus Cannartidiuin differs from Cannarti.'^ctts and Cannaiiiis in the duplica- 

 tion of the medullary shell, which is composed of two concentric spheres or compressed 

 lenticular spheroids. The three genera named form therefore one morphological series, 

 with identical cortical shell, and only differing in the absence or presence of a simple or 

 double medullary shell. 



Subgenus 1. Cannartiddla, Haeckel. 



Definition. — Surftice of the cortical shell smooth or a little rough, l)ut without spines 

 or fenestrated protuberances. 



1. Cannartidiuin ainpliiconicmn, n, sp. 



Cortical shell thick walled, smooth, with regular, circular pores, twice as broad as the bars ; 

 eight to nine on the lialf meridian, fifteen to sixteen on the half ec^uator of each chamber. Polar 

 tubes conical, with smaller pores, tapering towards the closed apex, about as long as one single 

 chamber, at the base one-third as broad as the equatorial constriction. Both concentric medul- 

 lary shells spherical. (Nearly identical with Cannartiscus avqihiconiscm, PI. 39, fig. 19, but differs 

 in the possession of the double medullary shell.) 



' C'((M)i((r/tVK«j)i - Small Ifiaf with tubules; y.xiux, cioTioion. 



