98 PROC. ENT. soc. WASH.. VOL. 22, NO. 5, MAY, 1920 



SOME ANATOMICAL DETAILS OF THE REMARKABLE WINGED 



ZORAPTERON, ZOROTYPUS HUBBARDIS CAUDELL, WITH 



NOTES ON ITS RELATIONSHIPS.* 



BY G. C. CRAMPTON. PH.D. 



Through the generosity of Mr. A. N. Caudell, I have been able 

 to make a morphological study of the winged Zorapteron de- 

 scribed by him in the preceding paper and to his general descrip- 

 tion of Zorotypus hubbardi, I would add the following supple- 

 mentary discussion of certain anatomical details of this remark- 

 able insect. Zorotypus is not only of great interest from the fact 

 that it is anatomically intermediate between the Isoptera and 

 Plecoptera, but it's position at the base of the line of descent of 

 the Psocidae (sensu lato] makes it an extremely important insect 

 for the study of the phylogeny of the higher forms as well. 



The head of a winged Zorotypus (Figs. 5 and 1) is very like that 

 of the small primitive Plecoptera Capnia, Leuctra, etc., in con- 

 tour, and is also somewhat suggestive of the head of a Psocid 

 in outline. Three ocelli "oc" (Figs. 5 and 1) are present in the 

 winged Zoraptera, and in their position and arrangement they 

 resemble those of the primitive Plecoptera mentioned above. I 

 do not find the ocelli in the blind, wingless forms, which I am 

 inclined to regard as the representatives of a caste distinct from 

 the winged forms, and if this be correct, the occurrence of castes** 

 in these insects is a feature very suggestive of affinities with the 

 Isoptera. 



The compound eyes of the winged Zoraptera usually exhibit 

 a darker pigmented central region surrounded by a whiter ring 

 as shown in Fig. 1, although merely the outline of the compound 

 eyes is shown in Fig 5. The frontal maculae "fm" (Figs. 5 and 

 1) occurring near the compound eyes of a winged Zorotypus, are 

 very similar to those of Capnia and other primitive Plecoptera, 

 and since they are not usually well developed in many 

 primitive orders of insects, they furnish additional evidence of 

 the affinities of the Zoraptera to the Plecoptera. The position 

 of the antennae (i. e., their attachment far down the front of the 

 head) is another feature in which the Zoraptera resemble the 

 primitive Plecoptera; but the outlines of the individual segments 

 are rather more like those of the antennae of the Embiidae (which 

 are very closely allied to the Plecoptera), although in regard to 



* Contribution from the Entomological Laboratory of the Massachu- 

 setts Agricultural College, Amherst, Mass. 



** Since this was written, Mr. Caudell has described the pigmented ap- 

 terous representatives of the group, which were unknown to me at the time 

 of writing. 



