184 THE AQUARIAN NATURALIST. 



foremost with considerable rapidity. Upon their 

 under surface the rays of the Comatula are furnished 

 with multitudes of vibratile cilia, which by their 

 action produce strong currents in the water, and hurry 

 along towards the mouth whatever floating particles 

 may happen to be in the vicinity, thus continually 

 affording an abundant supply of food. 



The evidence of Pentacrinus being the young of 

 Comatula rests upon a comparison of the most ad- 

 vanced state of the former with the youngest Coma- 

 tula procured by dredging. In the adult Penta- 

 crinus it will be observed, that the arms are just be- 

 ginning to form pinnse or lateral leaflets towards their 

 extremities, that they have a sulphur-yellow colour 

 and dark marginal spots. In the very young Coma- 

 tula these pinnse are but slightly further advanced, 

 and others may be observed sprouting in a manner 

 precisely similar. Individuals a little older are com- 

 paratively common, in which the pinnae are complete ; 

 and from this period they appear to be formed regu- 

 larly at the base of the arm, as this goes on extend- 

 ing in length. These small Comatulse, moreover, still 

 retain the original sulphur-yellow colour towards the 

 apices of the arms, while the lower part and body 

 gradually assume the rosy hue characteristic of the 

 adult animal. 



From observations repeatedly made, Mr. J. V. 

 Thompson thinks it probable that the young Coma- 

 tulse attain their full growth in one year, so as to be 

 in a condition to propagate their kind in the summer 

 following that of their birth. 



In May and June the full-grown Comatulse may be 



