134 



CEYLON MARINE BIOLOGICAL REPORTS. 



However it is evident that the most important difference between C. peltata and C. nummtdaria 

 lies in the structure of the shoots. An examination of both Harvey's original types and others shows 

 that nummularia always has this mode of growth and the accompanying structure of the shoots. That 

 also an occasional crenulate disc can be met with seldom is true, but this contributes much less to its 

 character than the mode of growth itself. The diameter of the assimilation discs varies, but can be 

 said not to exceed 5 mm. 



It must be observed that the big and splendid G. macrodisca, which is included by Weber v. 

 BossB as a variety of peltata, seems to have quite a different mode of growth. It has not procumbent 

 branches with all the assimilation discs on one level, but it seems to correspond in its mode of growth 

 with peltata. It also seems to grow in deeper water, since Weber v. Bosse mentions that she 

 had "dredged" it at the mouth of the Maros river, which may point to the fact that it does not belong 

 in every case to the uppermost part of the littoral zone. 



Geographical distribution. — Ceylon : in the upper part of the httoral zone on rocks and amongst 

 corals, in many places, at least on the south-west coast, but nev.er ocemring in large quantities ; thus, 

 around GaUe (in many places on the reef and rocks north-west of Victoria Park, but also amongst the 

 Madrepores below the Utrecht Bastion, and on stones at Watering Point) ! Indian Ocean ; Australia; 

 Pacific (Friendly Islands). 



Fig. 38. — C. imbricata (kjellm. 

 (1 X 1). 



Fig. 39. — C. imhricxUa 

 (KJELLM.) Flattened 

 branchlets. (3x1.) 



Fig. 37. — C. ?w?jr2cr<7rt (kjellm.). (1 x 1). 



17 —CAULERPA IMBRiCATA (Kjellman). 



Kjellman in WiTTROCK ET NoRDSTBDT, Algae Exsiccataj No. 346 (sub nonL Gliauvinia 



imbricata). 

 Murray, Catalogue p. 37. 

 Syn. Caulerpa peltata var. typica f. imbricata Webeb v. Bosbb, Monographic des Caulerpes; 



p. 375. 



Exstcc. : WiTTROCK BT NoRDESTDT, Alg. Exsicc. No. 346. 



f. minor. In all respects smaller and weaker. The size of the discs is upon an 



average 1 mm. in diameter (fig. 40). 



f. mixta. The basal branchlets cylindiical ; the upper ones are typicalimbricata — 



branchlets with the diocs sharply defined from the stalk (fig. 42). 



Under the name of Ghaumnia imbricata, Professor Kjellman described and distributed in Witt- 



ROCK ET Nordstedt, Algse exsiccatae. No. 346, a little Caulerpa from Galle in Ceylon, collected during 



the visit of the " Vega " expedition in the month of December, 1879. This Ghaumnia imbricata was 



afterwards included by Weber v. Bcsse as a form under C. peltata v. typica. As its character 



