340 COLLECTIONS FROM MELANESIA. 



Bome small bad specimens; they are respectively 200 and 220 

 miHim. (8 and 9 inches) long, extreme lateral extension in the natural 

 state probably about 70 miUim. (3 inches). This variety is remark- 

 able for its variability in external characters, for the great relative 

 length of the terminal branches, and the early stage at which branch- 

 ing commences, and by the ridged character of the face of the Blatt- 

 keule spicule ; in most other respects it closely approaches the 

 following variety. 



Plexaura prsBlonga, var. cinerea. (Plate XXXVIII. fig. h.) 



Growth upright, in one plane. Stem long. Branching approxi- 

 mately dichotomous ; branches few, flexuous ; terminal branches 100 

 to 150 millim. (4 to 6 inches) long ; stem and branches cylindrical, 

 approximately of one diameter, viz. about 2-3 miUim., throughout. 

 Cortex minutely rough, even, fairly tenacious. Colour in dry 

 state dark dirty grey. Verrucse small, slightly projecting from the 

 surface as low mounds, their openings extended in direction of length 

 of branch ; about 1 millim. distant from each other, equally distri- 

 buted all over cortex. Axis tough, flexible, glossy dark brown. 

 Cortical spicules : — (i.) Long fusiform, approximately straight, 

 tapering to sharp points, with scattered, tapering, sharp, simple 

 tubercles ; size -21 to -35 by '07 millim. (ii.) Stout fusiform-cylin- 

 drical, curved, rather thickly covered with low compound tubercles, 

 often extended in direction of circumference of spicule, with pointed 

 ends ; size about "3 by -12 millim. (iii.) Irregular tri- to sex- 

 radiate, the arms cylindrical, blunt, covered with few and scattered, 

 mostly low and blunt tubercles ; maximum diameter of spicule 

 •18 to "21 millim., thickness of arms "042 to "053 miUim. (iv.) 

 Blattkeule, extremely variable in form ; shaft provided with very 

 stout neck, generally branching into two (occasionally three) stout 

 arms ; the latter are well covered with compound, rather angular 

 tubercles, the neck and proximal part of foliar portion bearing 

 broader, more fungiform tubercles ; the foliar portion is flattened 

 in one plane, and either transversely oblong with four rounded 

 angles, or cordate with sharp lancet-like extremity, or with the 

 lower extremity prolonged into several long teeth ; the edges are 

 thin and always more or less dentate, at any rate at the outer 

 extremity, with small teeth ; the proximal part of the face carries, 

 as already mentioned, a few large, fungoid, compound tubercles ; 

 one variety which has the edges much dentate has also a number 

 of small tubercles extended almost as far outwards as the edges. 

 Size of spicule about -35 long by -35 millim. broad. 



ITah. Port Curtis, Queensland, 5-10 fms. ; bottom sand and 

 shells. 



This variety is represented by a single dry specimen, measuring 

 230 and 180 millim. (9 and 7 inches) in extreme height and diameter 

 respectively. It differs from var. typica chiefly in the tuberculate 

 rather than ridged character of the faces of the "Blatt" of the 

 Blattkeule spicule. 



