Australian Hydroids. 147 



bore two large sarcothecae abreast; the sixth bore on one side a 

 sarcotheca, and on the other a normal hydrocladium with its two 

 cauline sarcothecae, and the I'est were typical. Another branch 

 commenced similarly so far as the first and second internodes were 

 concerned, then followed one inter node, with two sarcothecae 

 abreast, the fourth supported one hydrocladium, and the remainder 

 two each. The branches originate at the side of the stem, between 

 two hydrocladia; the order of the hydrocladia is not disarranged, 

 and as the branch is thick it occiq^ies the wliole of the space betAveen 

 the two. 



EXPLANATION OF PL.ATES. 



Platk XTT. 



Fig. 1. — Sertulnria muelleri, n.sp. Front view. 



Fig. 2. — ,, ,, ,, Back view. 



Figs. 3-5. — ,. ,, ,,. (xouothecae. 



Fig. 6. — Sertiihiria tiirhhiata (Laniouroux). 



Fig. 7. — Sertidaria locidosn Bale. 



Fig. 8.- „ „ „ var. 



Fig. 9. — Sf.rf;idaria marginata (Kii-chenpauer). 



Fig. 10 — HebeMa scandenn (Bale), on Sipdhfcium rijliiKlrirnni 



(Bale). 

 Fig. 11. — Hehella cylivdrira (Von Lendenfeld), on Syntherivm 



alter nans A 11 man. 



(All niHgiiitied 40 diameters). 



Plate XIII. 



Fig. 1. — Ilalicornaria arcnata (Laniouroux). 



Fig. 2. — „ ,, ,, from the same colony. 



Fig. 3. — ,, ,, ,, middle of pinna. 



Fig. 4. — ,, ,, ,, end of pinna. 



Fig. 5. — Halicornnria ascidioides Bale. 



Fig. 6. — ,, ,, ,, end of pinna. 



Fig. 7. — Aylaojjhenui brevirostria (BusU). 



Fig. 8. — ,, ,, ,, fi'om .same colony. 



Fig. 9— 



Fig. 10. — Lytocarpua aurihiH (Busk). 



(All magnitied 80 diameters). 



