1096 THE VOYAGE OF H.M.S. CHALLENGES. 



1. Amphispyris thorax, n. sp. (PL 88, fig. 4). 



Shell thorax-shaped, as long as broad, with a deep sternal incision and two slight transverse 

 strictures. On each side of the ring-plane three pairs of large, irregular, annular holes of nearly 

 equal size, the middle holes nearly half as broad as the shell. No zygomatic bars between the orbital 

 and maxillary bars. Lateral lattice-girdle narrow, with few small roundish meshes. 



Dimensions. Shell 017 long, 017 broad, ring 0'06 long. 



Habitat. Central Pacific, Station 270, depth 2925 fathoms. 



2. Amphispyris quadrigemina, n. sp. (PI. 88, fig. 6). 



Shell shaped like the " corpora quadrigemina cerebralia," with two deep crossed strictures, a 

 coronal transverse stricture and a sagittal sternal stricture. On each side of the ring plane three 

 pairs of large, irregular, annular, double holes, the middle holes larger than the upper and lower 

 holes, and about one-fourth as long as the shell. No zygomatic bars between the orbital arid 

 maxillary bars. Lateral lattice-girdle broad, with numerous small meshes. 



Dimensions. Shell 013 long, 016 broad, ring 0'07 long. 



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



3. Amphispyris reticulata, Haeckel. 



Dictyospyris reticulata, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 289, Taf. x. 

 fig. 19. 



Shell thorax-shaped, one and one-fifth times as long as broad, with a deep sternal incision and 

 two distinct transverse strictures. On each side of the ring-plane three pairs of large annular holes 

 of nearly equal size, about one-third as long as the shell. No zygomatic bars between the orbital and 

 maxillary bars. Lateral girdle narrow, with few large polygonal meshes. 



Dimensions. Shell 018 long, 015 broad. 



Habitat. Indian Ocean, Zanzibar, depth 2200 fathoms (Pullen). 



Subgenus 2. Amphispyridium, Haeckel. 



Definition. On each side of the ring-plane four pairs of larger annular meshes ; 

 a middle horizontal zygomatic ring is developed between the two tympanic transverse 

 rings (superior orbital and inferior maxillary ring). 



4. Amphispyris sternalis, n. sp. (PI. 88, fig. 2). 



Shell thorax-shaped, one and one-fifth times as long as broad, with deep sternal incision and two 

 distinct transverse (tympanic) strictures. On each side of the ring-plane four pairs of large irregular, 

 annular holes ; the fourth (inferior or buccal) pair is the longest. The middle of the sagittal ring 



