PSYCHE. 



173 



united as in Phobetron, and showing an 

 alternation of strong and weak segments. 

 We have atrophy of the warts without 

 the loss of the primitive first stage. 



I class this type higher than type 4 

 because the warts have entirely disap- 

 peared and tiie structure is so modified 

 that there is no evidence in the individ- 

 ual ontogeny of the derivation from wart- 

 bearing ancestors ; but it is difficult to 

 compare the types exacth', as they are 

 so diverse and have pursued such differ- 

 ent lines of development. To this last 

 type belong both the European species. 



It might have been antecedently ex- 

 pected that the Australian type would 

 prove to be an ancient one from consid- 

 eration of the many other generalized 

 animals found in that countr}', yet such 

 is not the case. In fact tlie Australian 

 Eucleids are distinctly specialized, be- 

 longing to the highest phylum of the 

 horned larvae (type 3) and forming a 

 peculiar branch of that phylum, as the 

 following characters show : — 



The horns (hypertrophied warts) are 

 present in two rows, subdorsal on joints 

 3 to 13, lateral on joints 3, 4, 6 to 13 ; 

 the spiracle on joint ^ moved up into 

 the place of the missing horn ; skin with 

 irregular clear granules ; caltrope spines 

 present in little elliptical sunken patches 

 at the bases of the lateral horns of joints 

 6 to 13 and subdorsal of 13. So far the 

 larva stands just on a level with Eiiclea 

 indeterniina and Adoneia spinuloides 

 which have no detachable spines, lower 

 than Euclea delp/iinii and Sibine siim- 

 zilea which have them and again higher 



than Sisyrosea textitla and .S. tiasoni* 

 which do not possess caltropes. 



The shape is elongated, spaces equal 

 except the narrowed subventral space ; 

 feet as usual, the suckers showing dis- 

 tinctly on joints 5 to 11, apparently 

 absent on i3 and 13. Thoracic feet 

 small, distinct. The horns are unequal 

 in length as in Euclea, but the inequal- 

 ity is a special one. There are besides 

 two simultaneous modifications of the 

 original stinging spines. These are, 

 first, the formation of the retractile 

 horns and, second, the conversion of 

 the other horns into long smooth tenta- 

 cles. 



The first of these is indicated in some 

 of our own species, as in Sisyrosea 

 nasoni, where all the subdorsal horns 

 of joints 4 to 12 can be depressed out- 

 ward with convergence of all the spines 

 to a point, or, more exactl}' in Parasa 

 c/iloris where the subdorsal horns of 

 joints 4, T, II and i3 are bent in over 

 the back with the spines not erected. 

 In fact this rudimentary condition of 

 Parasa represents exactly the begin- 

 nings of the structure of the Australian 

 Eucleitls. Not only is the structure 

 similar, but it is the horns of the same 

 segments that are thus aflected. In 

 Doi-atifera. viihierans Lewin the re- 

 tractile horns are on joints 4, ^, 11, 12, 

 while in D. lezvini Scott anil D. casta 

 Scott they are on joints 4 and 5 only. 

 The retractile horns consist of a short 

 fleshy shaft with numerous spines which 



* The larvae which I call ytasotii have not yet been bred, 

 hence the determination is not certain. 



