REPORT ON THE RADIOLARIA. 533 



bhiiit convex end as broad as at the base. Patagiiim incomplete, with concave chamber-rows and 

 irregular network, only enveloping the basal half of the arms. 



Bivunsions. — Eadius of all three arms 0-15, basal breadth of each arm 00-i, terminal breadth 

 0-06. 



Habitat. — North Pacific, Californian Sea, depth 2600 fathoms, Ehrenberg. 



2. Euchitonia miilleri, Haeckel. 



Euchitonia miiUeri, Haeckel, 1862, Monogr. d. Radiol., p. 508, Taf. xxx. figs. 5-10. 

 Euchitonia miilleri, Slohr, 1880, Pateontogr., vol. xxvi. p. 110, Taf. v. fig. 5. 



Distance between the paired arms about two-thirds as large as tlieir distance from the odd arm, 

 which is somewhat larger. Length of the arms equals two and a half times the breadth of the 

 blunt convex end or five times the breadth of the base. Patagium with concave chamber-rows, 

 nearly complete, enveloping the arms with exception of the terminal face. (This common species 

 is very variable ; compare my Monograph.) 



Dimensions. — Eadius of all three arms 016 to 0-22, basal breadth 0'03 to 0-05, terminal breadth 

 0-06 to 0-08. 



Habitat. — Cosmopolitan ; one of the most common D i s c o i d e a in all seas, on the surface as 

 well as at different depths ; also fossil in the Tertiary rocks of Barbados and Sicily. 



3. Euchitonia trianyxdum, Haeckel. 



Sfijladis tnaiirjulnm, Ebrenbery;, 1872, Munatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 320; 



Abhandl.'d. k. Akad. d. Wiss. Berlin, Taf. viii. fig. 9. 

 Styladis trianrjulum, Stohr, 1880, Palffiontogr., vol. xxvi. p. 113, Taf. vi. fig. 2. 



Distance between the paired arms about two-thirds as large as their distance from the odd arm. 

 All three arms nearly of the same size and form, about one and a half times as long as broad, nearly 

 as broad at the base as at the blunt rounded end. Patagium incomplete, with convex chamber- 

 rows, enveloping about two-thirds of the arms. 



Dimensions. — Eadius of all three arms 015, basal breadth 0-05, terminal breadth 0-06. 



Habitat. — Pacific and Atlantic, Stations 253, 272, 354, surface ; also fossil in the Tertiary rocks 

 of Barbados and Sicily. 



4. Euchitonia cruciata, Stohr. 



Euchitonia cruciata, Stohr, 1880, Palseontogr., voL xxvi. p. Ill, Taf. v. fig. 7. 



Distance between the paired arms about one and a half tiriies as large as their distance from the odd 

 arm, which is a Ettle larger. Length of the arm nearly equals twice the breadth, which is the same 

 at the base and at the rounded blunt ends. Patagium incomplete, with concave chamber-rows, 

 enveloping only the base of the arms, and forms between them three other smaller arms; therefore the 

 whole shell forms six angles with six alternating arms. 



Dimensions. — Eadius of all three arms 015, basal breadth 0"05. 



Habitat. — Fossil in Tertiary rocks of Sicily, Grotte, Stohr. 



