

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



Dimensions. Main axes of the four shells (A) innermost O035, (B) second 0'08, (C) third 

 015, (D) outermost 0'2 ; their equatorial axes (A) 0'03, (B) O08, (C) 012, (D) 016 ; pores 

 0-004 to 0-016, bars 0'002 to 0'004. 



Habitat. Western Tropical Pacific, Station 198, depth 2150 fathom's. 



Subgenus 2. Caryodruppula, Haeckel. 



Definition. Shell composed of five or more concentric shells (two medullary and 

 three or more cortical). 



2. Cromyodruppa mango, n. sp. 



Shell composed of six ellipsoidal, concentric shells, two medullary and four cortical. Pro- 

 portion of their main axes = 2 : 3 : 8 : 11 : 14 : 18. Network of the two medullary shells and of 

 the innermost cortical shell subregular, with subcircular pores, about the same breadth as the bars. 

 Network of the three outer cortical shells more lax, with larger, irregular, roundish pores, twice to six 

 times as broad as the bars. The size of the pores and bars increases gradually from the innermost 

 ;to the outermost shell. Surface smooth. 



Dimensions. Main axis of the six shells (A) innermost 0'04, (B) 0'06, (C) 016, (D) 0'22 

 (E) 0-28, (F) 0-35; their equatorial axes (A) innermost 0'03, (B) 0'05, (G) 012, (D) 016, 

 <E) 0-2 ; (F) 0-25 ; pores 0'003 to 0'02, bars 0'003 to 0'005. 



Habitat. Indian Ocean, surface ; Matura, Ceylon, Haeckel. 



Genus 136. Cromyocarpus, 1 n. gen. 



Definition. D ruppulida with four or more concentric shells (two medullary 

 and two or more cortical shells), with numerous radial spines, but without polar tubes. 



The genus Cromyocarpus differs from Cromyodruppa only in the development of 

 numerous large radial spines which start from the outer surface of the shell. It 

 exhibits therefore the same relation to the latter that Prunocarpus bears to Prunulum, 

 or Druppocarpus to Druppula. It differs from both in the multiplication of the 

 cortical shell. 



1. Cromyocarpus quadrifarius, n. sp. 



Shell composed of four concentric shells, two ellipsoidal cortical shells, and two spherical 

 medullary shells. Proportion of their main axes = 10 : 8 : 3 : 2. Pores of the two cortical shells 

 irregular, roundish, twice to four times as broad as the bars. Pores of the two medullary shells 

 subregular, circular, about the same size as the bars. Outer surface covered with numerous 

 conical radial spines, about half as long as the main axis, half as broad at the base as the inner- 

 most shell. 



1 Cromyocarpus = Onion fruit ; x.(>ofivov, X.O.OKOS. 



