Fubi. ''i. X. 1911. SATURNIID.E. — General Subject. By Dr. K. Jordan. 209 



13. Family: Saturniidae. 



Although there are many forms among the Saturnids Avliich differ greatly in facies as well as in stmcture, 

 yet the family is sharply defined. The differences from allied families, such as Brahmaeidae, Bombt/cidae, Eiipte- 

 rotidae, etc., however, refer to venation only, as all the other characters which are generally mentioned as being 

 characteristic of the Saturnids s. lat. apply only to some of the species which belong here. 



Forewing with two to four subcostal veins, the two lower ones of which are on a common stalk; the 

 second radial of both wings always in or before the middle of the apex of the cell ; costal of hindwing free from 

 the base, neither connected with the cell by an oblique bar, nor anastomosed with it for a short distance, nor 

 curved down to near the apex of the cell; first submedian vein, freimlum and retinaculum absent; tongue 

 always weak, without function. 



The two halves of the tongue are separated, with irregular long fringes, and often altogether absent. Palpi 

 long and obliquely erect, or quite small and hidden in the wool of the head and forelegs, with all mtergradations, 

 often united at the base, without basal spot of modified hairs. Antennae also very diversely developed, usually 

 without scales, or the shaft sparsely covered with long scales which easily fall off, in some Neotropical genera 

 however (Lonomia, Draconopteris) densely scaled to the apex; the pectinations always without scales, in most 

 species first curved upwards, then sideways and downwards, but in the afore-mentioned American species 

 obliquely dowii-turned from their bases nearly as ua the Eupterotids and Lymantriids. Most species have 

 quadripectinate antennae in the (J, each segment of which (often with the exception of the distal ones) bears 

 a proximal and a distal pair of branches. Similar antennae are very rarely found outside this family (e. g., 

 among the Sphingidae in Cressonia and Monarda, and in the Eupterotids m Gangarides). In many cases the 

 distal branches of every segment are entirely absent; the distal and proximal pectinations are also never quite 

 alike. In the typical Saturnid antennae, whether bi- or quadripectinate, the thin and rather long sense-hairs 

 are situated on the distal side of the basal process and on the proximal side of the apical one, the upper and 

 lower hairs being directed respectively up- and downward. In the $ the antennae are quadri- or bipectinate 

 or dentate or simple, the teeth beuag shorter than in the ^ in all cases, and we may here mention the remark- 

 able fact that in many species with exceptionally strongly plumose cJ-antenna the ^-antenna has on the 

 contrary smaller pectinations or teeth than in allied species with smaller (^-antenna. Both sexes frequently 

 bear conical sensory organs at the apical edges of the segments, and often also on the pectinations, the cones 

 being in this family much more numerous than in others (sense-cones). 



The ocelli are always absent. The head is always retracted and small in proportion to the thorax and ab- 

 domen. The abdomen is more woolly in those species that spin a cocoon than in the forms which pupate in the 

 ground without a cocoon; in the latter species the long scales ai'e often hard and almost spiniform. 



The tibiae are always without spines. The spur at the inner side of the foretibia (epiphysis) often extends 

 nearly to the tip of the tibia, in other forms it is more or less reduced and sometimes entirely absent ; it is more 

 strongly developed in the ,^ than in the $. The spurs of the middle and hind tibiae are short and claw- 

 shaped in t3rpical Saturnids, their bare apical portion usually being finely dentate like the claws of the tarsi; 

 in many forms, however, the spurs of the tibiae are long, and a large number of species have a second pair, 

 or a single short spur representing this second pair (present in most Heterocera), on the limd tibia beside 

 the always present end-pair. The tarsi are never very densely spinose, and have generally no spmes at all 

 on the upper side; the short fourth segment of the fore tarsus of the $ is prolonged on both sides and here 

 bears a short stout spine ; the sole of segment 5 of this tarsus is in the 9 often only clothed with short hair. 

 The pulvillus is present and usually large, but is sometimes absent (e. g. in Hemileuca). The paronychium 

 has only one lobe on each side and is entirely obsolete in some genera (e. g., in Hemileuca, Eudia). 



The shape of the wings is extraordinarily variable. Among Othorene, Adelocephala, and other Cerato- 

 cam/jf rtaet he Sphingid-facies prevails; in many species of this subfamily of the Saturnids, especially in the $$, 

 the hhidwing has a similar shape as in Lasiocampidae. Long-tailed species occur in different groups of the family, 

 and sickle-shaped f orewings also occur independantly of each other in not closely allied genera. The discocellular 

 eye-spots, which in no other family are as abinidantly developed as in the Saturnids, are only preseiit in certain 

 groups and absent in the larger number of species. The difference ui the development of the venation is very 

 interesting, especially the reduction of the subcostal branches of the forewing from four to two, the various 

 stages of development being found m allied genera. We here mention incidentally that the subcostal branches 

 which morphologically correspond to branches 4 and 5 are always present, reduction taking place in subcostals 

 1 to 3. In some text-books the lower branch is erroneously described as being subcostals 4 and 5 fused together. 



II 27 



