REPORT ON THE RADIOL ARIA. 1285 



partly interrupted, longitudinal rows, separated by prominent crests. Month little constricted. 

 Peristome with twenty to twenty-four broad, lamellar, pointed feet, which are about as long as the 

 shell, little curved, and convergent. 



Dimensions. — Cephahs O'Ol long, 0-04 broad ; thorax 0'09 long, 0-09 broad. 



Halitat. — North Pacific, Station 244, depth 2900 fathoms. 



21. Carpocanium virginexcm, n. sp. (PI. 52, fig. 20). 



Shell ovate, smooth, with flat, perfectly hidden cephaJis. Length of the two joints = 1:8, breadth 

 = 3:9. Pores regular, circular, hexagonally framed, as broad as the bars, in about sixteen longi- 

 tudinal rows on each side. Mouth little constricted. Peristome with eighteen to twenty-four very 

 large, lamellar, pointed feet, which are longer than the shell, and so curved and convergent that 

 their distal points come nearly in contact. 



Dimciisioiis. — Cephahs O'Ol long, 0'03 broad ; thorax 0'08 long, 0'09 broad. 



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



Subfamily 2. Sethoph^nida, Haeckel, 1881, Proclromus, p. 433. 



Definition. — A n t li o c y i" t i d a with the basal mouth of the shell fenestrated 

 (vel Dicyrtida multiradiata elausa). 



Genus 570. Sethophcena,'^ Haeckel, 1881, Prodromus, p. 433. 



Definition. — S e t h o p h se n i d a {vel Dicyrtida multiradiata elausa) with lateral 

 apophyses. Cephalis with a horu. 



The genus Sethophcena and the following Clistophcena form together the small sul)- 

 family of Sethophsenida, comprising those Dicyrtida in which the thorax bears numerous 

 radial appendages (four to six or more), and the mouth is closed by a lattice-plate. In 

 SethophcBna the apophyses are lateral wings, as in Micromelissa, from which it may be 

 derived by development of secondary wings, interpolated between the three primary 

 wings. 



1. Sethophcena tetraptera, n. sp. 



Shell smooth, with deep coUar stricture. Length of the two joints = 3:10, breadth = 

 4 : 9. Cephalis subspherical, without horn. Thorax ovate, with rounded hemispherical base, and 

 subregular, hexagonal pores. From its upper half (below the collar stricture) arise four divergent, 



1 Se(/i«p/i(E?ia = Sieve-shell ; aviSu, (fxlua. 



