HEXACTINI^. FKOM NEW SOUTH WALES. 45 



teries, the second cycle. Even younger forms, having only ten tentacles 

 showed the second cycle of mesenteries developing. 



Haddon (9) also in 'describing larval forms of Halcampa crysantliellum, 

 which, like those of this larval form, had twelve mesenteries, found that at a 

 stage where the mesenteries 5 5, & &, were unattached in the lower 

 oesophagus there were present only eight tentacles. This is the more interest- 

 ing since Faurot (15) believes Haddon to be mistaken in the classification 

 and considers the larva described to be that of Peachia hastata. The fact 

 that the siphonoglyphe figured by Haddon continues below the oesophagus 

 certainly points in that direction. 



Our knowledge of the genus Peachia is very scanty. The description even 

 of the type species Peachia hastata is incomplete and contradictory. It is 

 first mentioned by Reid in 1848 (1) under the name of Actinia cylindrica, a 

 name preoccupied. Gosse renamed it Pmc/w'a Aastoto in 1855 (2). M'Intosh 

 (10) has described the commensal habits of the larval Peachia. From that 

 time its occurrence and external appearance have been noted by various 

 zoologists. Haddon and Dixon (7) summarize the literature to the date of 

 their paper and give an excellent account of the habits and external struc- 

 tures of this anemone. Haddon deduced the existence of pores in Peachia 

 from the grooves present externally on the physa oi Peachia hastata (7), which 

 he considered comparable with the external openings of pores in Halcampa. 

 " Mr. Dixon and myself are now satisfied that such (^. e. pores) is the true 

 explanation of the appearance we described in Peachia'' (7 and 8). He 

 included them in his definition of Peachia, but has not described them 

 further (11). But Faurot (15, p. 140) some nine years later in describing 

 the movements and actions of living Peachia hastata lays emphasis on his 

 opinion that the water with which it fills its body-cavity at this time is 

 ejected entirely by the mouth, by adding " un orifice a I'extremite basale 

 nexiste pas." That the apparent orifice caused by introversion, and mistaken 

 for a pore by older writers, is not one, is of course certain, but Faurot 

 overlooked the existence of these very numerous pores round the physa 

 oi Peachia hastata, which, indeed, may serve the very purpose of ejectino- 

 water. Still it is to Faurot (15) we owe most of our knowledge of the 

 internal anatomy of Peachia hastata. But his excellent paper on the com- 

 parative anatomy of several genera of Actinice does not profess to deal with 

 all their organs. In addition to the above omission, he does not mention the 

 powerful endodermal muscle-system of Peachia, denies the existence of a 

 sphincter^ and gives an account of several minor structures differing from 

 that given by Haddon. 



I have therefore dealt with the anatomy of all the organs of Peachia 

 hastata as fully as the condition of my material allowed. I have followed 

 Haddon (11) in describing the bulk of the muscle on the imperfect mesen- 

 teries longitudinal retractor. Faurot (15), on the other hand, considers that 



