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



sword-shaped, only two-thirds or one-half as long, and one-thu'd or one-fourth as broad, each with 

 two opposite teeth in the distal part. Central capsule ellipsoidal. 



Dimensions. — Length of the two major spines 013, breadth 0'02 ; length of the eighteen minor 

 spines 01. 



Habitat. — North Atlantic, Station 352, surface. . 



4. Amphilonche tenuis, Haeckel. 



Amphilonche tenuis, Haeckel, 1862, Monogr. d. EadioL, p. 389, Taf. xvi. fig. l,Taf. .xviii. fig. 16. 

 Acanthometra tenuis, Haeckel, 1860, Monatsber. d. k. Akad. d. Wiss. Berlin, p. 807. 



Two principal spines quadrangidar prismatic, with smooth edges, slightly or not at all prominent, 

 of equal breadth throughout their whole length ; apex simple or bifid ; base a small pyramid, without 

 leaf-cross. Eighteen smaller spines of the same form, but only one-fourth or one-third as long. 

 Central capsule spherical or ellipsoidal, colourless. 



Di7nc7isio7is. — Length of the two major spines 0"2 to 0'3, of the eighteen minor spines 0"05 to 01. 



^ixfeitei.— Mediterranean (Messina) ; Atlantic, Station 354, Canary Islands, surface. 



5. Amphilonche dentic^data, Haeckel. 



Amphilonche denticulafa, Haeckel, 1862, Monogr. d. Radiol., p. 390, Taf. vi. fig. 2, Taf. xviii. 

 fig. 17. 



Two principal spines quadrangular prismatic, with prominent, elegantly denticulated edges, of 

 equal breadth throughout their whole length ; apex simple or truncated ; liase a small pyramid, 

 without leaf-cross. Eighteen smaller spines of the same form, but only one-fourth or one-third as 

 long. Central capsule ellipsoidal, opaque, yellowish-brown. 



Dimensions. — Length of the two major spines Oo to 0'4, of the eighteen minor 01 ; breadth of the 

 former 0-009, of the latter 0-006. 



Habitat. — Mediterranean (Messina), Haeckel, surface. 



6. Amphilonche heteracantha, Haeckel. 



Amphilonche heteracantha, Haeckel, 1862, Monogr. d. EadioL, p. 293, Taf. xvi. fig. 7. 

 Acanthometra heteracantha, Haeckel, 1860, Monatsber. d. k. Akad. d. \Vi.ss. Berlin, p. 803. 



Two principal spines quadrangular prismatic, very large, with four broad, prominent, lamellar 

 edges, of equal breadth throughout their whole length. Apex as well as the base a four-sided 

 pyramid. Eighteen smaller spines very thin, conical, with bristle-shaped apex ; base a small pyramid, 

 without leaf-cross. Central capsule cylindrical or violin-shaped, opaque yellow. 



Dimcnsio7i.s. — Length of the two major spines 0-2 to 0'3, breadth 0-015 to 0-02 ; length of the 

 eighteen minor spines 0-1 to 0-15, basal breadth 0-004 to 0-008. 



Habitat. — Mediterranean (Messina); Central Pacific, Station 271, surface. 



