Manchester Memoirs, Vol. Ixv. (1921), No. 11 9 



Pontoniinae. I am, however, inclined to dissent from this 

 conclusion. It is unlike the Pontoniinae prawns in several 

 features. Foremost of these is its telson, which has quite a 

 different facies. To that may be added certain features of the 

 mouth-parts which, as I have shown, are in some respects 

 unlike those of the Pontoniinae and suggest affinities with 

 some of the families which connect the Palaemonidae with the 

 Crangonidae. The uncleft outer flagellum of the antennule is 

 also a point of difference from the Palaemonidae, but this might 

 quite well be due to retrogression connected with a sheltered 

 life, and is approached in some Pontoniinae. The inflated 

 carapace a little suggests that of the Hippolytid Pterocaris, 

 but this likeness is belied by the whole of the rest of the 

 anatomy. 



Taking the evidence as a whole, I am inclined to place 

 Paratypton near the point to which the Palaemonidae, 

 Anchistioididae, and Gnathophyllidae converge, but I think 

 that it would at present be rash to attempt to define its position 

 more precisely than this. 



The problem is complicated by the fact that the structure of 

 the prawn is obviously greatly modified bv its unusual mode 

 of life. This is of course conspicuouslv true of its habit of 

 bodv. Others of its features, such as those of the mouth-parts 

 and chelae, do not differ from those of free-living forms more 

 than the latter differ among themselves, and it is at present 

 impossible to say how far, if at all, their peculiarities are 

 connected with trie habit of living in a coral-gall. 



