EEPORT ON THE RADIOLAEIA. 1151 



widely divergent, straight, twice as long as the shell-diameter. Three lateral wings broad, each 

 with a basal row of few very large irregular roundish meshes, and several distal rows of small 

 square meshes. This species is very similar to Clathrocorys mttrrayi (PI. 64, fig. 8), but has no 

 trace of thorax-wall. The latter species may be derived from the former by development of the 

 thoracic lattice, which connects the three free feet. 



Dimensions. — Shell 0*05 long, 0'06 broad. 



Habitat. — Central Pacific, Station 266, depth 2750 fathoms. 



3. Archiscenium tripterygiwm, n. sp. 



Shell hemispherical, smooth, with numerous irregular roundish meshes of very different sizes. 

 Basal lattice with four large meshes, two major cardinal and two minor cardinal pores. Apical 

 horn and the three feet of similar form and size, slender prismatic, three to four times as long as 

 the shell ; the horn straight, the feet curved. Three lateral wings very delicate, with a basal row 

 of few large irregular polygonal meshes, and several distal rows of similar small pores. 



Dimensions. — Shell 0'04 long, 0'05 broad. 



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



4. Archiscenium cyclopteruvi, n. sp. (PL 98, fig. 3). 



Shell hemispherical, with small irregular roundish pores. Basal lattice with four large meshes, 

 two major cardinal and two minor jugular pores. Apical horn and the three feet of similar form 

 and size, slender prismatic, straight, twice to four times as long as the sheU. Three lateral wings 

 nearly semicircular, densely latticed, with the same pores as the shell, and smooth convex margin. 



Dimensions. — Shell 0'05 long, 0'06 broad. 



Habitat. — South Pacific, Station 295, depth 1500 fathoms. 



5. Archiscenium callimitra, n. sp. 



Shell campanulate, with irregular polygonal pores. Basal lattice with nine meshes (three larger 

 central and six smaller distal pores, as in Calliynitra carolotw, PL 63, fig. 8). Apical horn straight, 

 prismatic, slender, conical, twice as long as the shell. Feet longer and more slender, slightly 

 curved. Three lateral wings very broad, densely fenestrated, with irregular polygonal pores of the 

 same shape as in the similar Callimitra carolotw (PI. 63, fig. 1). 



Dimensions. — Shell 0'05 long, 0'04 broad. 



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



Genus 507. Pteroscenium} Haeckel, 1881, Prodromus, p. 429. 



Definition. — A r c li i p e r i d a (vel Monocyrtida triradiata clausa) with a free 

 branched internal cohimella, prolonged into an apical horn. Three basal feet connected 

 with the horn by three vertical lateral wings. 



1 Pteroscenium = Small tent witli wings ; •jrri^oi/, <ix.nviou. 



