202 HYDROIDS FROM NEW SOUTH WALES. 



take them out of the plane of the stem; soon, however, they take a 

 characteristic curve upward, become erect, and divide into two 

 equal branches with their anterior aspect directed towards that of 

 the stem. Each successive branch grows in the same manner. The 

 liydroclades are borne on the anterior of the stem and branches, 

 often only one on an internode on the distal part of a branch. 

 Sometimes an internode occurs with three hydroclades. 



Another striking feature is the angularity of the hydrotheea, 

 especially at the base where the thickened adcauline wall makes a 

 very abrupt angle, and even in many cases is prolonged past the 

 actual base of the cell. The apocauline wall meets the base at 

 almost as sharp an angle, while the base itself is straight. The 

 cliitinous projection within the mesial sarcotheca is well-developed, 

 swelling out as soon as it passes beyond the point of attachment 

 of the sarcotheca. The latter organ has a very wide basal portion, 

 and is based on the much elongated proximal part of tlie internode. 



Locality. — Maroubra Bay, near Sydney, N.S.W. 



Type Specimen. — In the Australian Museum, Sydney. 



EXPLANATION OF PLATES XXX.-XXXT. 



Plate XXX. 



Fja. 1. Sertulardla ritchid Briggs, part of stem with hydrothecw and 



base of branch, x 20. (After Ritchie). 



Fig. 2. Sertvlarella ritchiei Briggs, part of stem with hydrothecte, x 33. 



Fig. 3. Halicornaria gojiiodes Briggs, portion of hydroclade with hydro- 



thecse, lateral aspect, x 48. 

 Fig.4. Halicornaria goniodes Briggs, portion of hydroclade with hydro- 



thecse, anterior aspect, x 62. 



Ficr.5. Halicornaria goniodes Briggs, hydrotheea, lateral aspect, x 90. 



Fig.6. Halicornaria goniodes Briggs, hydrotheea, anterior aspect, x 80. 



Yxg.!.— Halicornaria goniodes Briggs, part of stem with the bases of four 



hydroclades, anterior aspect, x 30. 

 Plate xxxi. 

 Y\g.\.~ Halicornaria goniodes Briggs. Photograph of the type, 28cm. 



in height, from Maroubra Bay, near Sydney, N.S.W. 

 Fig.2. Sertularella ritchiei Briggs. Photograph of colonies from "Thetis' 



Station 22, Newcastle Bight, N.S.W., 40-26 fathoms. Nat. size. 



CORRIGENDUM. 

 The legend of Plate xxx. should read :— 

 \.2.Sertidarella ritchiei, nom.nov. S-1. Halicornaria goniodes, n.sp. 



