HOUTMAN ABEOLHOS ISLANDS. 175 



star-fish and these practically all Ophiuroidea. In contrast to the hauls at 

 almost all other places, weobtained but few sponges and fewer ascidians. 



Our most interesting finds were obtained by shore-collecting on llie outer 

 reef, starting from the southern extreme end of Pelsart Island and working 

 south and west. At this spot we obtained the first specimens of any 

 Enteropneust to be recorded from the West coast of Australia. They were 

 found in the coarse sand which lies in a few places, sheltered in shallow 

 hollows on the reef-flat close to the lagoon. On both expeditions we 

 obtained them by sifting the sand through the fingers, and nowhere else but 

 here on the Pelsart Reef were we successful in finding any. The animals 

 were translucent and of a pale yellow colour. They varied in size, one 

 of the larger specimens measuring 12 centimetres when somewhat con- 

 tracted. After fixation very great .contraction takes place and dimensions 

 of fixed specimens are of little value. The species has been described 

 by the author in another paper, and is regarded as a new species of the 

 genus Ptychodera allied to P. flava. It has been called Ptychodera pelsarti 

 after the famous voyager whose ship was wrecked on the group now bearing 

 his name *. 



On the same reef, in close proximity to the spot where Ptychodera occurs, 

 we found a large species of Pagurid particularly common — each shell bearing- 

 three or four large anemones. The gephyrean Bonellia was found for the 

 first time on the coast of West Australia. It has since turned up several 

 times on the coast, off Fremantle, but the species has not yet been investigated. 



The Pelsart Atoll seems to be a particularly happy ground for Echinodermata. 

 Several species of Echini occur on the floor of the lagoon, each occupying its 

 own area. A very fine species, resembling the English Echinus esculentus in 

 size, occurs in immense numbers on the floor of the lagoon at the southern 

 end of the atoll. In another region not far from this we passed over large 

 numbers of Asterids. Very few Aloyonaria have been obtained from the 

 Abrolhos, and so far as our collections go these were all obtained on the 

 Pelsart Group. Some were collected on the reef near its extreme southern 

 point, whilst others were abundant on the northern shores of the islets termed 

 the Mangrove Islands on the chart. 



Some of these islands, together with the coral reefs, form a small well- 

 sheltered area known by the fishermen as Whale's Bay. It is entered by a 

 narrow channel from the north, and, as it is quite close to the open sea and 

 in a very suitable position for departures to Geraldton, it is well frequented 

 by the fishermen, who anchor there for the night. I was informed that the 

 spot was well known to the fishermen as a place to which whales resorted to 

 scrape off their attached barnacles. The skipper of our lugger said that they 

 had on more than one occasion had a whale scraping itself against the anchor 



* Journ. Linn. Soc, Zool. xxxiii. (1916) pp. 85-100, pis. 10, 11. 

 LINN. JOURN. ZOOLOQY, VOL. XXXIV. 13 



