REPORT ON THE RADIOLARIA. 1185 



about one-third as long as the shell. Mouth truncate, without peristome, about half as broad as 

 the shell. 



Dimensions. Shell 015 long, 01 broad ; horn 0'05, mouth 0'05. 



Habitat. Central Pacific, Station 268, depth 2900 fathoms. 



3. Archicorys microstoma, n. sp. (PL 51, fig. 12). 



Shell rough, thick-walled, ovate. Pores large, subregular, circular, twice to four times as broad 

 as the bars. Horn small, conical, not larger than one pore. Mouth very small, truncate, scarcely 

 larger than one pore. 



Dimensions. Shell 01 long, 0'07 broad; horn 0'012, mouth 0'015. 



Habitat. Western Tropical Pacific, Station 225, depth 4475 fathoms. 



4. Archicorys globosa, n. sp. 



Shell nearly spherical, thorny, thick-walled. Pores very large, circular, separated by spinulate 

 frames, smaller towards each pole. Horn conical, large, nearly as long as the radius of the shell ; 

 mouth truncate, simple, about one-third as broad as the shell. 



Dimensions. Shell diameter 013, horn 0'06, mouth - 04. 



Habitat. Fossil in Barbados. 



5. Archicorys ovata, n. sp. (PI. 51, fig. 10). 



Shell ovate, rough, thick-walled. Pores regular, circular, of equal size, very small and numerous, 

 (juincuncially disposed. Horn small, conical, sometimes (as in the figured specimen) rudimentary. 

 When it becomes lost, the species may be called Cyrtocalpis ovata. Mouth truncate, small, simple, 

 one-sixth as broad as the shell. 



Dimensions. Shell 0'2 long, 015 broad ; horn O'Ol -to 0'03 long, mouth 0'03 broad. 



Habitat. Central Pacific, Station 266, depth 2750 fathoms. 



Genus 529. Cyrtocalpis, 1 Haeckel, 1860, Monatsber. d. k. preuss. Akad. 



d. Wiss. Berlin, p. 835. 



Definition. Archicorida with simple urceolate or ovate shell, constricted 

 towards the mouth. Apex without horn. 



The genus Cyrtocalpis comprises a large number of common, very primitive Monocyr- 

 tida, which in the simple ovate or urceolate form of the shell resemble the well known 

 Gromia among the Thalamophora. Its basal mouth is more or less constricted, as in 



1 Cyrtocalpis= Basket-urn or wicker-pitcher ; xiifroj, X*XT/(. 



(ZOOL. CHALL. EXP. PART XL. 1886.) Rr 149 



