1478 THE VOYAGE OF H.M.S. CHALLENGER. 



each of the following joints ; in each of the former three to four transverse rows, in each of the 

 latter six to eight transverse rows of small, regular, circular pores. 



Dimensions. Length of the shell (with six joints) 0'09, of the three first joints 0'03, of the three 

 .following 0'06; breadth of the sixth joint 0'08, of the fourth 0'04 



Habitat. Mediterranean (Candia) Spratt, depth 1620 fathoms. 



7. Dictyomitra demersissima, Haeckel. 



Eucyrtidium demersissimum, Ehreiiberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, 

 Taf. vii. fig. 11. 



Shell slender, conical, smooth, with four internal septal rings (without external strictures). 

 Breadth of the five joints gradually increasing, length unequal ; the third joint the longest, twice as 

 long as the second, and longer than any of the following. Pores very small and numerous, in longi- 

 tudinal rows. 



Dimensions. Length of the shell (with five joints) 0'09, of the second joint O'OIS, of the third 

 0'03; breadth of the second joint O03, of the third 0'05. 



Habitat. Tropical Pacific, Philippine Sea, depth 3300 fathoms. 



Subgenus 3. Dictyomitroma, Haeckel. 



Definition Shell with longitudinal ribs and furrows between them, with joints of 

 different lengths. 



8. Dictyomitra costata, n. sp. 



Shell slender, conical, with prominent longitudinal ribs, and six to eight deep strictures. Length 

 of the majority of joints nearly equal, the two or three first joints shorter, the last a little longer. 

 In each joint only a single transverse series of pores at the distal end (one pore in each furrow). 

 (Similar to Siphocampe tubulosa, PL 79> fig. 13, but conical, and without cephalic tube.) 



Dimensions. Length of the shell (with eight joints) 016, of each middle joint 0'03, of the first 

 0-02; breadth of the last joint 0'06. 



Habitat. Central Pacific, Station 295, depth 1500 fathoms. 



9. Dictyomitra multicostata, Zittel. 



Dictyomitra multicostata, Zittel, 1876, Zeitschr. d. deutsch. geol. Gesellscb., p. 81, Taf. ii. 

 figs. 2-4. 



Shell slender, conical, with prominent longitudinal ribs, and eight to ten deep strictures. Length 

 and breadth of the joints gradually increasing, the eighth joint twice as long and broad as the fourth 

 joint. Pores regular, circular, one series in each longitudinal furrow, three to four pores on each 

 joint. 



