1094 THE VOYAGE OF H.M.S. CHALLENGER. 



the latter genus is a simple lattice-plate, it here becomes more or less spongy, and some- 

 times forms a very dense and delicate wickerwork. The apical horn and the three basal 

 feet are commonly also fenestrated. The two annular strictures, which separate the 

 cephalis from the conical cupola and the inflated thorax, are commonly not so distinct 

 as in the preceding genus. Some species belong to the largest Spyroidea and reach 

 more than half a millimetre in length. 



1. Lamprospyris darwinii, n. sp. (PL 89. fig. 13). 



Shell nearly pear-shaped, with two distinct annular strictures, and uneven papillate surface. 

 The total length is equal to twice the greatest breadth, and to seven times the length of the ring. 

 Apical horn free, irregularly branched and fenestrated, as long as the included columella beyond it. 

 The three diverging feet are strongly curved, S-shaped, and completely included by loose lattice-work. 

 In the middle of their length they give off a simple strong lateral branch. The loose arachnoidal 

 lattice-work is rather equally developed. 



Dimensions. Length of the entire shell (including the apophyses) 0'5, greatest breadth O25, 

 ring 0'07 long. 



Habitat. Central Pacific, Station 271, depth 2425 fathoms. 



2. Lamprospyris lyellii, n. sp. 



Shell slender, pear-shaped, very similar to the preceding species, but differing in the following 

 characters the branched horn is much larger and twice as long as the columella ; the two annular 

 transverse strictures (separating the three joints) are deeper. The free lateral branches of the three 

 included feet are forked. Lattice-work looser than in the preceding species. 



Dimensions. Length of the entire shell 0'6, breadth O2, ring 0'09 long. 



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



3. Lamprospyris huxleyi, n. sp. (PL 89, fig. 14). 



Shell ovate, spiny, with two slight annular transverse strictures ; their length equal to one and a 

 half times the breadth, and up to seven times the length of the ring. Apical horn quite included 

 by the loose lattice-work of the large conical cupola, which is as long as the cephalis and thorax 

 together. The three slender feet are also included in the lattice-work and only one-third as long 

 as the shell, nearly vertical. Lattice-work much denser than in the two preceding species. 



Dimensions. Length of the shell 0'4, breadth 0'26, ring 0'06 long. 



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



4. Lamprospyris hooJceri, n. sp. 



Shell ovato-conical, very similar to the preceding species, but smooth, not spiny. The apical 

 horn and the three feet are much longer, not included in the network, but freely prominent, half 



