175 
which are twice as broad as long in the said species (Comp. figs. 
35.1-2 and 3 - 5 ). The oral shields are much larger, and the space 
covered with grains inside the oral shields smaller than in P. gra- 
cilis. Also the spines are shorter and more flattened in cylindrica. 
¥ 
The ventral plates do not present marked differences in the two 
species. Finally it would appear that P. cylindrica grows to a some- 
what larger size than P. gracilis. The figures of the two species 
were drawn from specimens of nearly the same size in order to 
eliminate differences solely due to age. 
Fig. 36. Pectinura gracilis Mrtsn. ; specimen from Three Kings Isl. Part of oral side, 
and base of arm, dorsal side, with part of the disk. ^o/i. 
The two species appear to have the same distribution along the 
Northern coasts of New Zealand, from Three Kings Island to Cooks 
Strait. Whether this holds good also for the Southern coasts is still 
uncertain; only P. gracilis has been recorded from Stewart Isl. and 
thus evidently is distributed all along the coasts of the South Is¬ 
land. Recently I received from Prof. Ben ham some specimens of 
P. cylindrica'' from Stewart Isl.; they proved, however, to be P. 
gracilis. The facts at present available would thus seem to indicate 
that P. cylindrica does not extend so far South as P. gracilis. 
After the above was written I received from Mr. W. R. B. 
Oliver a specimen stated to be the type of Hutton’s Ophiura 
cylindrica. There is no doubt but that this specimen belongs to the 
species described here as P. gracilis^ not to the one here named 
Pectinura cylindrica (Hutton) in accordance with the figures and 
description of the latter, given by F a r q u h a r (Op. cit.). According 
