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



stomatous types existed in Palaeozoic times ;"^ although in the Mesozoic and Tertiary strata 

 fossil Cheilostomata are numerous. The palseontological evidence as to the antiquity 

 of the Cyclostomata is fuUy confirmed and strengthened by the embryological researches 

 that have recently been so carefully and accurately made by various authors ; for instance 

 M. Barrois ^ says that the study of the structure of the larva and of the formation of 

 the cell coincides with palaeontology in furnishing us with perfectly concordant results, 

 which are conclusive as to the antiquity of the Cyclostomata. Many of the species even 

 have a wdde distribution in time, for out of the thirty-three included in this collection, 

 fourteen have already been identified in the fossil state. 



No fossil forms belonging either to the Ctenostomata or to the Entoproctan Polyzoa 

 have hitherto been identified, but Mr. Vine has thrown out a hint, in a paper on 

 Ascoclictyon,^ that perhaps Ascodictyon' filiforme may be a primitive representative of 

 the stoloniferous Vesiculariadse, or possibly of the Entoprocta. That this latter order is 

 of great antiquity is also confirmed by its embryonic history, for the same eminent 

 authority, above quoted, M. Barrois,* after the most careful and elaborate comparison of 

 the larvae of the various Ectoproctan and Entoproctan groups, comes to the conclusion 

 that " the larvae of Entoprocta represent the primitive type from which all the others are 

 derived." 



A.— NOETH ATLANTIC EECION. 



Station 75, lat. 38° 38' N., long. 28° 28' 30" W.; 450 fathoms; volcanic mud. 

 Idmonea milneana, C. | Idmonea irregularis. 



Cape Verde Islands, 100 to 120 fathoms. 



Horner a frondiculata. 



Station 36, lat. 32° 7' 25" N., long. 65° 4' W., ofi" Bermuda; 30 fathoms; coral. 

 Crisia denticulata, var. patagonica. \ Amathia lendigera. 



Cape Verde Islands, 10 fathoms. 



Crisia conferta, D. 



Station 109, 0° 55' 38" N., long. 29° 22' 35" W., ofi" St. Paul's Eocks ; shallow water. 



Crisia denticulata, B, D. 



1 Vine, Quart. Journ. Geol. Soc, vol. xL p. 332, 1884. 



2 Barrois, Ann. and Mag. Nat. Hist., ser. 5, vol. x. p. 391 (footnote). 



3 Vine, Ann. and Mag. Nat. Hist., ser. 5, vol. xiv. p. 87. 

 * Barrois, loc. cit., p. 401. 



