REPORT ON THE RADIOLARIA. 1325 



'J. Dictijoci')-as formica, n. sp. (PI. 71, fig. 8). 



Shell with obliterate collar, but deep lumbar stricture. Length of the three joints = 1 : 2 : 3, 

 breadth = 2 : 5 : 4. C'ephalis conical, with an oblique curved horn of the same length. Thora.x 

 with three vaulted swellings between the three prominent, diverging lattice-wings, the apex of 

 which is prolonged downwards into a solid curved spine, half as long as the inflated abdomen. 

 Jlouth little constricted. Pores irregular, roundish, of different sizes. 



Dimensions. — Length of the three joints, a 0-02, b 0'0-4, c 0'06 ; breadth, a 0'03, h 01, c 0'09. 



Habitat. — Xorth Atlantic, Station 353, surface. 



3. Dictyoceras melitta, u. sp. (PL 71, fig. 9). 



Shell with two deep strictures. Length of the three joints = 1 : 3 : 4, breadth = 1 : 6 : 5. 

 Cephalis subspherical, with two conical divergent horns of_tlie same length. Thorax three-sided 

 pyramidal, the three edges prolonged into three lattice-wings of the same form, with short, terminal 

 spines. Abdomen inflated, subovate, with constricted mouth. Pores small, regular, circular, of 

 equal size, with very thin bars. 



Dimensions.— 'Length of the three joints, a 0'03, b 0'09, c 012 ; breadth, a 0'04, b 018, c 015. 



Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 



4. Dictyoceras hombus, n. sp. (PL 71, fig. 10). 



Shell with deep collar, but evanescent lumbar stricture. Length of the three joints = 1 : 5 : 3, 

 breadth = 1:6:7. Cephalis subspherical, with a conical horn of the same length. Thorax cam- 

 panulate, with three short and broad, triangular lattice-wings, the upper edge of which is nearly 

 horizontal, the lower nearly vertical and decurrent from the height of the collar to the lumbar 

 stricture. Abdomen inflated, with constricted mouth of half the breadth. Pores small, subregular, 

 circular, of nearly equal size. 



Dimensions. — Length of the three joints, a 0'02, b 01, c O'OG ; breadth, a 0'025, b 012, c 014. 



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



5. Dictyoceras vircliowii, Haeckel. 



Dictyoceras virchoicii, Haeckel, 1862, Monogr. d. Radiol, p. 333, Taf. viii. figs. 1-5. 

 Lithomithium dictyoceras, Haeckel, 1860, Monatsber, d. k. preuss. Akad. d. Wiss. Berlin, 1860, 



p. 840. 



Shell with two distinct strictures. Length of the three joints = 1:3:4, breadth = 1:5:6, 

 Cephalis subspherical, with an oblique curved horn of the same length. Thorax conical, with tliree 

 broad, triangular lattice-wings different in size and direction, two of which are directed outwards, 

 the third downwards — each terminated by a strong sphie. Abdomen oblique, inflated, with wide 

 open, truncate mouth. On the shell surface some few conical spines are .scattered. Pores irregular, 



