1414 THE VOYAGE OF H.M.S. CHALLENGER. 



8. Tricolocampe doliolum, n. sp. 



Shell cylindrical, with hemispherical apex, rough. Length of the three joints = 1:3:5, breadth 

 = 1:2:3. Cephalis spherical. Thorax and abdomen cylindrical, of nearly equal breadth. Mouth 

 widely open, not constricted. Pores irregular, roundish, in the abdomen three to four times as 

 large as in the thorax, disposed in oblique rows. 



Dimensions. Length of the three joints, a 0'03, b 0'09, c 0-16 ; breadth, a 0'03, b 0'05, c 0'09. 



Habitat. Fossil in Barbados. 



9. Tricolocampe cingulata, n. sp. 



Shell subcylindrical, with obtuse conical apex, thick-walled. Length of the three joints = 

 2 : 3 : 11, breadth = 3:7:8. Cephalis hemispherical, not separated externally from the short conical 

 thorax, but with internal collar septum. Abdomen cylindrical, with wide open, non-constricted 

 mouth. Pores in the thorax narrow, obliquely ascending, in the abdomen twice as large, circular, 

 arranged in ten to twelve regular transverse rows, separated by slight strictures. Lumbar septum 

 nearly complete. 



Dimensions. Length of the three joints, a 0'02, b 0'03, c 01 to 012; breadth, a 0'03, b 0'07, 

 c 0-08. 



Habitat. Fossil in Barbados, and in Tertiary rocks of Sicily ; living in the depths of the Atlantic 

 and Central Pacific, Station 348, depth 2450 fathoms ; Station 268, depth 2900 fathoms. 



10. Tricolocampe arcta, Haeckel. 



? Eucyrtidium arctum, Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 33. 

 1 Lithocampe arcta, Haeckel, 1862, Monogr. d. Radiol., p. 317. 



Shell subcylindrical, with obtuse conical apex. Length of the three joints =1:2:4, breadth = 

 1:2:2. Cephalis subspherical. Thorax campanulate, separated by a deep collar, but a slight 

 lumbar stricture. Abdomen cylindrical, with wide truncate mouth. Pores in the thorax narrow, 

 obliquely ascending, in the abdomen half as large, very small, and densely disposed in six to eight 

 regular transverse rows. 



Dimensions. Length of the three joints, a 0'022, I 0'045, c 0'09 ; breadth, a 0'026, b 4 05, c 0'05. 



Habitat. Central Pacific, Station 266 to 274, depth 2350 to 2925 fathoms. 



Genus 619. Theocorys, 1 Haeckel, 1881, Prodromus, p. 434. 



Definition. T heocorida (vel Tricyrtida eradiata aperta) with ovate abdomen, 

 broader than the constricted mouth. Cephalis with a single horn. 



The genus TJieocorys and the two following closely allied genera, united formerly 

 with Eucyrtidium, differ from the preceding Theocorida in the constriction of the 



1 17ieocor2/s=Divine helmet ; hoi, 



