Mr. Hassall on the Branched Freshwater Conferva. 359 



it. The anal contains only two spines, unless the anterior short one 

 has been removed in preparing the specimen. The pointed ventral 

 reaches to the anus. The margin of the caudal is slightly concave, 

 the angles rather acute, and the upper one projecting a very little. 



The colours of the specimen are tolerably well preserved, and 

 agree generally with the tints mentioned in the * Histoire des Pois- 

 sons.' 



The scales of the back and sides are dark and show greenish tints, 

 and each is sharply bordered by a dark purplish margin producing a 

 regular meshwork : there are faint traces of a paler crescent on each 

 scale within the marginal one. The under surface of the body, 

 bounded by a line running from the axilla of the pectoral to the 

 anal, is pale, each scale having also a pale margin, though of a dif- 

 ferent tint from the disc. There is a large circular violet-purple 

 blotch behind the eye, a dark patch on the preorbitar, and some 

 spots of campanula-purple on the preoperculum, suboperculum and 

 interoperculum. The cheeks and operculum have a dull yellowish 

 hue. The colours of the pectorals and ventrals are effaced, except 

 that a dark mark remains on the base of the former. The dorsal and 

 anal fins are imperial purple, which is bounded by a line of deep 

 pansy-purple, the extreme border being pale. Many dots of pansy- 

 purple are spread over both fins, being roundish on the anal and ob- 

 long on the soft dorsal ; a few larger drops extend to the pale bor- 

 der of the anal, and the scales on the base of the fins are edged with 

 emerald-green. The caudal is purplish without spots, its edge being 

 pale. 



Dimensions. inches, lines. 



Length from upper teeth to end of caudal 13 6 



base of caudal 11 3 



anus 6 9 



dorsal 4 9J 



ventrals 4 6 



pectorals 4 2 



end of lobe of gill-cover ;.. 4 3 



orbit 2 3 



Diameter of eye 7 



Height of body 3 Q 



[To be continued.] 



L. — Observations on the Growth, Reproduction, and Species 

 of the Branched Freshwater Confervce. By Arthur Hill 

 Hassall, Esq. 



In a paper read before the Natural History Society of Dublin, 

 a portion of which was inserted in the e Annals/ vol. ix. p. 431. 

 allusion was made to the principal mode of growth of the 

 freshwater Confervae, viz. by the continued growth and bi- 

 section of all the cells entering into the formation of the fila- 

 ments. I come now to notice a second mode of development, 



