326 



THE VOYAGE OF H.M.S. CHALLENGER. 



Ophiothrix virgata. 



trilineata. 



melanosticta. 



striolata. 



elegans. 



suensonii. 



capillaris. 



purpurea. 



viridialba. 



plana. 

 Ophiogymna elegans. 

 Ophiocnemis marmorata. 

 Ophiomaza cacaotica. 



obscura. 

 Ophiothela mirabilis. 



dance. 



isldicola. 

 Ophiopsammium semperi. 

 Opioblenna antillensis. 

 Ophiohelus umhella. 

 Ophiomyces fr utec tos us. 

 Qpldomyxa peniagona. 

 flaccida. 



Oph io myxa aust ; 'alls. 

 Hem ie \ t / y/< ( le p list ulata. 

 Sigsbeia murrhina. 

 Astrophyton costosum. 

 svinosum. 



JL. 



nudum. 

 coecilia. 

 clavatuin. 

 exiguum. 

 jxniamense. 

 Gorgonocephalus arboresct ;ns. 

 cacaoticus. 

 verrucosus. 

 Eunjale aspera. 

 Trichaster palmiferus. 



elegans. 

 Astmcitida isults. 

 Astroporpa annxdata. 



affinis. 

 Astroschema oligactes. 

 tenue. 

 keve. 

 Ophiocreas lumbricus. 



There are not enough observations to render the preceding tables complete or accurate, 

 but their general conclusions are perhaps reliable. Table I. gives the species of cold water ; 

 Table II. those of temperate ; and Table III. the warm water species. The last, which also 

 are of comparatively shallow water, are by far the most numerous, a proportion which 

 suggests that heat, light, and small pressure tend to produce variety in form and structure ; 

 and yet there is not that vast difference between deep cold species and shallow warm 

 ones which might reasonably be looked for on the theory that so called natural forces 

 are alone potent to effect change. 



If the present faunse of the two sides of the Isthmus of Panama, as compared together, 

 have varied so little since the Chalk ; or if some deep Atlantic species present no greater 

 changes than they do as compared with the Triassic or the Chalk species, how is it that 

 Ophiuridse have thus dragged along in narrow limits, while some other animals have 

 almost unbelievably changed ? Perhaps we shall be told that it is their nature to drag 

 along, just as Moliere's medical student says that opium produces sleep because it pos- 

 sesses a somniferous property. 



