138 THE VOYAGE OF H.M.S. CHALLENGER 



furrows, which are most distinct round the periphery. Colour hyaline to porcellanous, 

 lustrous. Spire — each whorl is a little below the level of the one which follows ; but the 

 Apex, which is mamillate, small, and glossy, rises distinct in the middle and is not 

 introverted (as in Bifrontia zanclea, Phil.) Whorls nearly four, convex, small ; they are 

 contiguous, except the last, which towards the mouth is separated from the one which it 

 lies beside. Suture well impressed. Mouth small, round, but with a slight tendency to 

 angularity. Lip thin, rather patulous on the inner side. Umbilicus includes the whole 

 shell, and exposes all the whorls ; it is a good deal more impressed than the upper side 

 of the shell. H. 0-042 in. B. 0-097. Mouth, height 0-042, breadth 0-039. 



It is possible this shell may be a Bifrontia, as I have named it, but I do not believe it to be 

 so. Still less, however, do I think it a Scrpularia, and I do not know what else to call it. So till 

 something more is known of the shell and of the animal than I have learned from the three Challenger 

 specimens, I think it safest to class it as I have done. 



3. Trachysma, G. O. Sars, 1878. 

 Trachysma delicatum (Philippi). 



Cyclostoma? delicatum., Philippi, Enum.'Moll. Sicil, vol. ii. p. 222, pi. xxviii. fig. 3. 

 Trachysma „ G. O. Sars, MolL Arct. Norv., p. 212, No. 125, pi. xxii. figs. 17, 18. 



Station 75. July 2, 1873. Lat. 38° 38' N., long. 28° 28' 30" W. Fayal, Azores. 

 450 fathoms. Volcanic mud. 



Station 78. July 10, 1873. Lat. 37° 26' N., long. 25° 13' W. San Miguel, Azores, 

 1000 fathoms. Volcanic mud. 



Station 122. September 10, 1873. Lat. 9° 5' S., long. 34° 50' W. Pernambuco. 

 350 fathoms. Eed mud. 



Habitat. — Mediterranean (Philippi) and North Atlantic (Sars). 



This species was got by the " Porcupine " expedition in the North Atlantic. The generic name 

 is a MS. one of Dr J. Gwyn Jeffreys, but was first published by Sars. 



Family Scalariime, Broderip, 1839. 

 Genera. 1. Scalaria, Lamarck. 2. Crossea, A. Adams. 

 1. Scalaria, Lamarck, 1801. 



Species. 



1. Scalaria aculeata, Sow. 6. Scalaria vermetiformis, n. sp. 



2. Scalaria jukesiana, Forb. 7. Scalaria pMltata, n. sp. 



3. Scalaria tortilis, Wats. 8. Scalaria (Cirsotrema) hellenica, Forb. 



4. Scalaria acus, Wats. 9. Scalaria (Cirsotrema) denliscalpium, Wats. 



5. Scalaria funiculata, Wats. 10. Scalaria (Acirsa) subdecussata, Cant. 



11. Scalaria (Acirsa) pyrrhias, n. sp. 



