REPORT ON THE RADIOLARIA. 1237 



rows of pores, the upper six rows three to four times as large as the lower six rows. From its upper 

 half diverge almost horizontally three angular club-shaped wings, half as long as the shell 



Dimensions. Cephalis O05 long, 0'06 broad ; thorax 0'06 long, O05 broad. 



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



2. Peromelissa psilocrana, n. sp. 



Shell smooth, very similar to the preceding species in size and form, but differing from it in the 

 disposition of the irregular, roundish pores, which are irregularly scattered, and in the form of the 

 three wings, which are slender, pyramidal, diverging downwards, and about as long as the entire shell. 



Dimensions. Cephalis 0'07 long, 0'06 broad ; thorax 0'07 long, 0'06 broad 



Habitat. Central Pacific, Station 272, depth 2600 fathoms. 



3. Peromelissa capita, Haeckel. 



Lithomelissa capita, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iii. fig. 14. 



Shell rough, with two joints of nearly equal size and similar ovate form. Pores irregular; 

 roundish, everywhere scattered. From the upper half of the thorax arise three short conical wings, 

 which are little curved and diverge downwards (scarcely half as long as the breadth of the shell). 



Dimensions. Cephalis 0'07 long, 0'06 broad ; thorax 0'07 long, 0'06 broad. 



Habitat. Fossil in Barbados. 



4. Peromelissa calva, n. sp. (PI. 57, fig. 12). 



Shell rough, with two ovate joints of somewhat different sizes. Pores irregular, roundish, every- 

 where scattered. Thorax little larger than the oephalis ; from its upper half arise three short 

 conical wings, diverging downwardly or nearly horizontally. 



Dimensions. Cephalis 0'06 long, 0'04 broad ; thorax 0'7 long, 0'05 broad. 



Habitat. South Atlantic, Station 332, depth 2200 fathoms. 



Genus 554. Sethomelissa, 1 Haeckel, 1881, Prodromus, p. 431. 



Definition. S ethoperida (vel Dicyrtida triradiata clausa) with three divergent 

 latticed lateral wings. Cephalis with a horn (or a bunch of horns).. 



The genus Sethomelissa differs from the nearly allied Micromelissa in the fenestra- 

 tion of the three lateral wings, and may be derived either from this genus by develop- 

 ment of lattice-work connecting the three wings with the shell, or perhaps from 

 Clathrocanium by closing the mouth. 



1 Sethomelissa = Sieve-bee ; aii$a, fahiatct. 



