214 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



THUIARIA QUADRIDENS Bale 



Thuiaria quadridens Bale, Australian Hydroid Zoophytes, 1884, p. 119, 



pi. 7, figs. 5, 6. 

 Thuiaria quadrilateralis Hargitt, Hydroids of the Philippine Islands, 1924, 



p. 493, pi. 5, fig. 17. 



The specimens secured by the Albatross are very much like those 

 described by Bale in detail, although their manner of growth is 

 parasitic, being found on a plumularian hydroid and growing from 

 a creeping root stalk from which erect and undivided branches arise. 

 The details of the hydrothecae, however, appear to correspond quite 

 exactly with T. quadridens, and I therefore feel it best to refer it to 

 that species. 



The figures given by Bale and Hargitt are so nearly identical that 

 I have little hesitation in relegating T. quadrilateralis to synonymy. 



Gonosome. — This was found by Hargitt on his specimens and 

 described as follows : " Gonangia large, several times the size of the 

 hydrothecae, and a four-sided shape, borne on short pedicels of 

 pinnae, none on stems of my specimens." 



Locality. — Dredging station 5251, Gulf of Davao, Linao Point, 

 7° 5' 12" N., 125° 39' 35" E. ; depth, 28 fathoms. 



Distribution. — Australia, Port Curtis (Bale) ; Philippine Islands 

 (Hargitt). 



DICTYOCLADIUM ABERRANS, new species 



Plate 41, figs. 4, 5 



Trophosome. — Colony 8 cm. in height and with a spread of 2>y 2 

 cm., flabellate in form. Main stem fascicled proximally, but simple 

 for the greater part of its length, without nodes ; branches alternate. 



Hydrothecae in pairs, the pairs being separated by more than 

 their height and the bases of the individual hydrothecae are nearly 

 contingent proximally but divaricate distally. On the main stem 

 the hydrothecae are arranged so that there is one above and one 

 below each branch origin and one opposite each branch origin. Occa- 

 sionally there are three Irydrothecae in a whorl and on one branch 

 there are uniformly four of them in a whorl. The individual 

 hydrothecae are flask-shaped with the distal ends curving grace- 

 fully outward, the margin square and with four low teeth as in 

 many species of Sertularella, and there are also annular marks 

 ("Ringfalte" of Stechow) around the margin. Operculum of four 

 equal triangular flaps. 



Gonosome. — On another specimen a single gonangium was found. 

 It is extremely elongated, almost cylindrical in shape, about four 

 times as long as wide, with walls distinctly but not deeply annu- 

 lated, distal part narrowing insensibly into a broad marginal collar. 

 The margin is impaired and seems to have four teeth. 



