1070 THE VOYAGE OF H.M.S. CHALLENGER. 



be derived from Petalospyris by loss of the original apical horn. The feet are commonly 

 numerous, and often form a circle around the margin of the basal plate, similar to the 

 circle of tentacles in many Medusse (Gorgon). 



Subgenus 1. Gorgospyriuni, Haeckel. 

 Definition. — Feet simple, not branched. 



1. Gorgospyris medusa, n. sp. (PI. 87, fig- !)• 



Shell hemispherical, papillate, with slight sagittal stricture and subregular circular pores. 

 Basal plate with three large collar pores (by mistake not correctly represented in the figure). Ten 

 to twelve slender feet, twice as long as the shell, strongly curved and divergent, of equal length. 



Dimensions. — Shell 0-06 long, 0-08 broad ; feet 0-1 long. 



Habitat. — North Pacific, Station 241, depth 2300 fathoms. 



2. Gorgospyris medusetta, n. sp. (PI. 87, fig- 2). 



Shell nut-shaped, smooth, with deep sagittal stricture and irregular, roundish pores. Basal 

 plate with three large collar pores, alternating with three pairs of smaller pores. Sixteen to twenty 

 slender feet, about as long as the shell, slightly curved and divergent, of nearly equal length. 



Dimensions. — Shell 0-05 long, 0"08 broad; feet 0-05 long. 



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



3. Gorgospyris ehrenhcrgii, Haeckel. 



Petaloqjyris pentas, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berhn, p. 80, Taf. xxii. 

 fig. 11. 



Shell nut-shaped, smooth, with sUght sagittal stricture and unequal circular pores. Basal 

 plate with three large central pores, alternating with three pairs of smaller pores, and with a peri- 

 pheral circle of smaller pores. Twenty-four to thirty short truncated feet, shorter than half the 

 shell. 



Dimensions. — Shell 0'05 long, 0"07 broad ; feet 0"02 long. 



Habitat. — Fossil in Barbados. 



4. Gorgospyns polypus, n. sp. (PI. 87, fig. 3). 



Shell hemispherical, papillate, with slight sagittal stricture and subregular circular pores. 

 Basal plate with four larger and four alternating smaller pores. Feet sixteen to twenty, slender, 

 curved, divergent ; four primary feet larger, twice to three times as long as the shell and the other 

 feet. 



Dimensions. — Shell O'OS long, Q-l broad ; feet Ol to 0'2 long. 



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



