170 Transactions of the Society. 



Third Variety (plate V. fig. 11). — One pair of long, strong 

 spines on the anterior trunk. Very few small spicules on body. 

 Imperfectly studied. 



Habitat. — Katoomba. 



Fourth Variety, var. brevispinosa. — Differing from the African 

 form in having 4 transverse dorsal rows of spicules on central 

 trunk. There are some additional spines on the anterior trunk. 

 The ventral surface is distinctly transversely plicate. 



Callidina serrulata sp. n., plate V. figs. 7a, lb. 



Specific Characters. — Of moderate size, papillose ; teeth 2 ; trunk 

 bearing many lanceolate serrate processes, in pairs, and some stout 

 spines, spicules, and ligular processes. 



Length, creeping 350/x, width of trunk 125 p,, neck 48/x, processes 

 up to 50 p or more in length. 



Eelated to C. pinniycra, the processes are more numerous, 

 longer, and taper to acute points, instead of being fan-shaped and 

 truncate. Most of them are serrate. The second anterior trunk 

 segment has a pair of stout spines, with broad conical bases ; a 

 smaller pair of stout spines at widest part of central trunk. The 

 head and foot are as in C. multispinosa and pinniycra. 



Habitat. — Katoomba, Blue Mountains. 



Callidina mirabilis sp. n., plate V. figs. 8a-8d. 



Specific Characters. — Size moderate ; trunk broad, bearing many 

 paired excrescences, apparently produced by a secretion ; anterior 

 margin of trunk with three large fleshy processes, one median, two 

 lateral. Head small, disks narrow ; sulcus deep, narrow ; collar 

 prominent; antenna moderate ; teeth, about six ; rump with several 

 conical spiny processes, and two posterior, broad flanges. Foot 

 short ; spurs narrow, straight, tapering, divergent, with wide inter- 

 space. 



Length 350 p,, width of trunk 150 p,, corona 80 p., neck 60 p,, 

 tip to tip of spurs 28 p,. 



Tubercles on trunk like those of M. incrassata and D. macrostyla 

 form tuberculata, irregular, some capped by flat plates. Antenna 

 stout ; rostrum short, broad, constricted below ; teeth very strong, 

 jaw with broad border. 



The fleshy processes of the anterior trunk are the strangest 

 feature of the animal, and require further study. The lateral ones 

 are strongly curved outwards, and along the convex border there is 

 a prominent band, which is transversely striate. The central 

 process has a large median pore. It could not be seen whether it 

 had a striate border. 



One of the most specialized of the Philodinadte, this species 



