A SYNOPSIS OF AL'STRAMAN ACARINA — KAINPOW. 161 



line, luiHiiny down the alxlomen ; this has two hiteral branches at 

 its anterior extremity. On the underside the colour is a httle 

 ligliter than above. Genital Opening. — Near posterior extremity. 

 •Suckiiiy Discs. — On each side, twelve. Lec/s. — Not strong, 

 rather long; fourth pair somewhat the longest; all provided with 

 swinnning hairs. Coxal or Epiyneral Plates. — Three, united to 

 the venter. Length of body 1-9 mm., breadth 1-2 mm. 



Hab. — Parramatta, in ponds, June, 190.5 (Mr. A. R. IVIcCul- 

 loch). 



Ohs. — Species of the Molluscan genus Dijjlodon, 8pix, occur in 

 fresh-water ponds around Parramatta, and they are frequently 

 infested with Acarids. The lattei*, however, are scarcely 

 pai'asitic, as they feed on minute animals drawn in by the 

 mollusc. 



Fa^nihj HALACARID^ 



Several species of Halacaridae have been recorded from Aus- 

 tralia and adjacent islands, and as all of these are pelagic, it is 

 only natural to expect such forms (or at any rate, some of them) 

 to have a wide geographical range. Those occurring on the shores 

 of New Guinea and the North Island of New Zealand, for 

 instance, may certainly be expected to occur here. These 

 Acai'ids are minute, ranging from one to two millimetres in length. 

 They are found upon Algse, Corals, Crustaceans and Cliitons, 

 often in shallow water, although some have been di edged at 

 considerable depths. Halacarids have a tough skin, which may 

 be striated or granulated, and most frequently destitute of hairs 

 or bristles. The body is usually clearly divided into two parts, 

 and the ceplialothorax has usually three eye-spots — one on each 

 side and one at the middle in front. Legs are moderately long, 

 rather widely separated at the base, and lateral or sub-lateral in 

 origin. Each tarsus terminates with two claws. Some Hala- 

 caridas occur in fresh water, and some in brackish. 



Genus Agaxie, Lohm 



Agaue brevipalpus, Troues. 



A(/aiie brevipalpus, Troues., Naturaliste, xi., 1889, p. 181 ; Bull. 

 Sci. France Belgique, xx., 1889, p. 247 ; Lohmann in Ergeb. 

 Plankton Exped., ii., 1893, p. 87 ; Trouessart, Bull. Soc. 

 Zool. France, xxv., 1900, p. 47. 



Hosts. — Algag and Corals 



7/rt6.— Pacific Ocean, Sydney, New South Wales ; also Mediter- 

 ranean Sea ; Atlantic Ocean ; Azox-es, Canaries, Bermudas, Bi-azil. 



