184 p. A. BUXTON. 



only, gamma. Beta and delta appear to be absent. In front of the large pro- 

 thoracic spiracle an immense tubercle (g.t.) arises, pointing forwards. It is clothed 

 with setae of both types, the brown and the colom-less, which are more than half 

 as long as the entire larva, and are directed forwards over the head. This verruca 

 is very well developed in various Liparid larvae which I have examined, and is 

 formed by the fusion of Rho and Kappa. This we see when we compare the pro- 

 thorax with either of the succeeding segments, in both of which Rho and Kappa are 

 separate. The process of fusion of these two verrucae, so complete on the pro- 

 thorax, can actually be watched taking place on successive segments of the abdomen. 

 Beneath this very large verruca is a second one, which consists of Pai with its asso- 

 ciated setae ; this is recognisable in all segments to the ninth abdominal inclusive. 

 Its setae project outwards and downwards and form a conspicuous tuft over the leg 

 on all leg-bearing segments. 



Meso- and metathorax. The chaetotaxy is sufficiently shown in text-fig. 1 (B). 

 Rho and Kappa are not fused. 



Abdomen. Beta (a, plus ft, plus secondary setae) can be seen on each of the 

 first nine segments and is largest on the eight and ninth. The gradual migration 

 of Kappa to a position behind but distinctly above the spiracle is interesting. It 

 never coalesces completely with Rho except on the ninth segment, but the two 

 groups, Rho and Kappa, are borne on one large partly divided verruca on all the 

 abdominal segments. The group which represents sigma consists of many setae, 

 and is borne on a definite verruca on the legless segments (1, 2, 7, 8, and 9) ; on the 

 other segments it is only to be found with difficulty. No trace can be found of nu, 

 tau, or mu ; we presume therefore that they are components of Pai. 



The legs and prolegs are covered sparsely with secondary setae which are believed 

 to be of no phylogenetic significance. The prolegs (A and C, pi.) are long and armed 

 with long crochets all of one size arranged in a mesoseries, that is to say a curved 

 fine concave outwards. On the outer side of all prolegs except the anal pair is a 

 chitinous plate bearing secondary setae. The dorsal glands on abdominal segments 

 6 and 7 are small ; the diameter of the mouth of the gland is less than verruca Beta ; 

 these glands are believed to be characteristic of all Liparidae. 



The points of interest in the structure of the larva are : — 



(1) Liparid larvae fall into two main groups : Ocnerogyia amanda falls into the 

 first, many of which are densely hairy Hke Arctiidae. The second group contains 

 bizarre species armed with dense brushes (verricules) and clavate plumed setae ; 

 Orgyia is a good and famihar example of this group. 



(2) Tracker states that in these insects there are " three verrucae above the Kappa 

 group on the mesothorax and metathorax." Forbes says (p. 103) " five warts on 

 mesothorax." (This comes to the same thing as beneath Kappa lies Pai). Ocnerogyia 

 amanda forms an exception to these general statements ; as will be seen from text- 

 fig. C, there are only four verrucae on the mesothorax, and metathorax ; two of 

 which are above Kappa. 



(3) The eversible gland on the mesodorsum of abdominal segments 6 and 7 

 appears to be the most constant characteristic of the larvae of Liparidae. So far 

 as we know, it is always present, though it may be very small. 



