(38) 



and gradually diminish in size towards the sui-face, where they are 

 minute. Substance, "when fresh, cartilaginous, but soon becoming- 

 flaccid when removed from the water." Fructification : simple, elongated, 

 moniliform pods (or stichidia), attached to the whorled filaments by a 

 short footstalk, and containing at maturity, in each joint, an elliptical 

 olive-coloured spore, "which at length bui'sts through the membrane 

 and falls away." Colour, a fine transparent olive-green, rapidly changing 

 to a dirty yellow in decay ; adheres firmly to paper in drying. 



This beautiful and delicate species is more common on our southern 

 than on our northern shores, becoming rarer as we proceed northwards ; 

 and in Scotland is by no means common. The whorled filaments with 

 which the joints of this species are furnished, are almost identical with 

 those that fringe the fronds of Desmarestia ; and Professor Hai-vey 

 remarks, that the fructification of both genera is very likely of the 

 same nature, although no fructification, so far as we are aware, has yet 

 been observed on any species of Desmarestia. 



We are informed by Dr. Greville, that Mr. Hassell observed " that this 

 species had the property of rendering the paper on which it was spread, 

 transparent for a short time. Most of the species of SjMrochnoidece 

 have also the property of staining the paper of a fine brown colour, 

 and rapidly decompose other delicate species with which they are left 

 in contact after being removed from the water. 



EXPLANATION OF PLATE CXLIV. 



Fig. 1. — Arthrodadia villosa, natural size. 

 2. — Whorled branches of the stem. 

 3. — Pinnae from same. 

 4. — Longitudinal section of stem. 

 5. — Transverse section of same. 

 6. — Sporiferous filaments. All magnified. 



