1118 THE VOYAGE OF H.M.S. CHALLENGER. 



1. Lithobotrys geminata, Ehrenberg. 



Lifhobotrys geminata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p 76, Taf. iii. 



fig. 19. 

 Lithobotrys geminata, Biitschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 519, Taf. xxxiii. 



fig. 27, a to e. 

 1 Lithocori/thium platylophus, Ehienberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, 



Taf. iv. fig. 5. 



Cephalis trilobate, with a single apical tube in the apex of the helmet-shaped occipital lobe, 

 which is one and a half times as long as the two subspherical frontal lobes. Thorax ovate, one and 

 a half times as long as the cephalis, with few small pores in six to eight transverse rows. 



Dimensions. Length of the shell O'l, breadth 0'05. 



Habitat. Fossil in Barbados. 



2. Lithobotrys lithocorythium, Haeckel. 



Lithocorythium oxylophus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, 



Taf. iv. figs. 3, 4. 



ILithopera oxystauros, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iii. 

 fig. 6. 



Cephalis trilobate, with a single apical horn or a pointed tube in the apex of the helmet-shaped 

 occipital lobe, which is a little longer than the two ovate frontal lobes. Thorax ovate, about as 

 long as the cephalis, with very numerous and small pores. 



Dimensions. Length of the shell 0'08, breadth 0'04. 



Habitat. Fossil in Barbados. 



3. Lithobotrys nasuta, Ehrenberg. 



Lithobotrys nasuta, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iii. fig. 21. 



Cephalis quadrilobate, with a single descending sternal or nasal tube on the base of the anterior 

 or frontal lobe, which is half as long as the helmet-shaped occipital lobe and twice as large as the 

 two lateral buccal lobes. Thorax ovate, twice as long as the cephalis. Pores rather large, 

 circular. 



Dimensions. Length of the shell Oil, broad 0'05. 



Habitat. Fossil in Barbados. 



4. Lithobotrys ornata, Ehrenberg. 



Lithobotrys ornata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iii. fig. 18. 



Cephalis quinquelobate, with two divergent ascending tubes, a posterior occipital and an anterior 

 sternal or nasal tube. Occipital lobe campanulate, twice as large as the two frontal, and four times 

 as large as the two buccal lobes. Thorax ovate, twice as long as the cephalis. Pores scarce and 

 small. The specimen figured by Ehrenberg is very incomplete. 



Dimensions. Length of the shell 0'09, breadth O05. 



Habitat. Fossil in Barbados. 



