REPORT ON THE RADIOLARIA. 1231 



The genus Lychnodictyum differs from the preceding Lychnocanium only in the 

 fenestration of tlie three terminal feet, and bears therefore to it the same relation that 

 the ancestral Tripocyrtis does to Dictyophimus, 



1. Lychnodictyum challengeri, Haeckel. 



Dictyopodium challengeri, Wyville Thomson, 1877, Atlantic, voL i. p. 234, fig. 52. 

 Didyophimus (vel Tripocyrtis) rJiallengm-i, Haeckel, 1878, Protistenreich, p. 47, fig. 35. 



Shell campanulate, smooth, with sharp collar stricture. Length of the two joints = l:3, 

 breadth = 1:4. Cephalis siibspherical, with a large, oblique, pyramidal horn thrice the length. 

 Thorax with three inflated bosoms between the three decurrent ribs, which are prolonged into tln-ee 

 vertical, parallel, pyramidal, in the upper half fenestrated feet, as long as the thorax. Pores regular, 

 circular. Mouth constricted, flat, half as broad as the thorax. 



Dhnamons. — Cephalis 0'03 diameter; thorax 0'08 long, 0'12 broad. 



Habitat. — Tropical Atlantic, Station 338, depth 1990 fathoms. 



2. Lychnodictyum wyvillei, n. sp. 



Shell pyramidal, smooth, witli obhterated collar stricture. Length of the two jomts = 1:3, 

 lireadth = 1:5, Cephalis subspherical, with a large, straight, pyramidal horn of ■ twice the length. 

 Thorax nearly tetrahedral, inflated, with three rounded, decurrent ribs, which are prolonged into three 

 widely divergent, angular, curved feet, about as long as the shell, with pyramidal fenestrated base. 

 Pores regular, circular. Mouth constricted, flat, half as broad as the thorax. 



DimensioTis. — Cephalis 0'025 diameter; thorax O'OS long, 0"12 broad. 



Habitat. — Central Pacific, Stations 266 to 274, depth 2350 to 2925 fathoms. 



3. Lychnodictyum scaphopodium, n. sp. (PI. 56, fig. 4). 



Cephalis hemispherical, large, without liorn, with irregular, small, roundish pores. Thorax a 

 little larger, campanulate, with three broad, shovel-shaped, fenestrated, vertical feet, and larger, 

 irregular pores. In the figured specimen the third (posterior) foot was broken off. In another speciT 

 men the three feet were somewhat longer and not so broad. 



Dimensions. — Cephalis 0"03 long, 0'05 broad ; thorax 0'05 long, 0'06 broad. 



Habitat. — Central Pacific, Station 274, depth 2750 fathoms.. 



4. Lychnodictyum sethopodium, n. sp. 



Cephahs hemispherical, large, with a rudimentary conical horn, and very scarce small pores. 

 Thorax twice as broad and long as the cephalis, campanulate, with irregular, roundish pores, and 

 three slender, pyramidal, divergent feet twice the length, which in the upper half are fenestrated, 

 in the lower half solid. 



Birmnsions. — Cephalis 0'025 long, 0'045 broad ; thorax G'05 long, 0'09 broad; 



Habitat. — South Atlantic, Station 330, surface. 



