8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 85 



AYSHEAIA Walcott 191 1 



AYSHEAIA PEDUNCULATA Walcott 



Plate II 



Aysheaia peduncidata Walcott, 1911, Smithsonian Misc. Coll., vol. 57, p. 117, 



pi. 23, figs. 8-9. 

 Aysheaia pedunculata Hutchinson, 1930, Proc. U. S. Nat. Mus., vol. 78, art. 11, 



p. 14. 



This fossil has perhaps attracted wider attention than any other. Recently 

 G. E. Hutchinson, of Yale University, studied this peculiar form and concluded 

 that Aysheaia is an extinct Onychophora. Unfortunately, Mr. Hutchinson did not 

 see the two individuals here illustrated, as they were buried away among 

 numerous specimens of Ottoia. As the present assemblage of material progressed 

 they came to light and are now illustrated, especially as they are perhaps the best 

 preserved specimens available. 



At the time these photographs were found among the notes Doctor Walcott 

 intended using in further publications relating to this animal, two letters were 

 discovered, both suggesting that Aysheaia may be an Onychophora or a Perip- 

 atus. The first letter, dated September 21, 191 1, was written by Prof. W. M. 

 Wheeler of Harvard University, and reads as follows : 



" I wish to thank you for your very interesting publications on the Middle 

 Cambrian Annelids. On plate 22, I noticed two figures of Aysheaia pedunculata. 

 This creature bears the most extraordinary resemblance to Peripatus, except for 

 the head, and judging from the figures the 'head' may be something which 

 does not belong to the fossil. I have just shown these figures to Mr. C. T. Brues, 

 who has been working on Peripatus, and he also was struck with the remarkable 

 resemblance. Is there any possibility that it might be Peripatus instead of an 

 Annelid? If this should prove to be the case it would be a matter of the very 

 greatest interest." 



The second letter dated October 25, 1911, was written by Prof. Charles 

 Schuchert, of Yale University, and contains the following : 



" The other point is one that Lull has called my attention to and refers to 

 figures 8 and 9 of plate 2^ which you call Aysheaia pedunculata. The question 

 that I want to ask is, have you considered it as a possible Onychophora or 

 related to Peripatus? Of course if one looks at your illustrations and compares 

 them with the illustration of Peripatus given by Parker and Haswell in their 

 Text-book of Zoology, page 607, in the edition of 1910, one can see considerable 

 differences and yet there are in your figures several points in common to 

 make one wonder whether you have not a marine ancestor of this land-living 

 arthropod." 



This rather lengthy historical account is presented to show that at least three 

 authorities arrived at the same conclusions independently. 

 Plesiotypes. — U. S. N. M., Nos. 83942a-b. 



LEANCHOILIA Walcott 1912 



LEANCHOILIA SUPERLATA Walcott 



Plate 12; plate 13, figs. 1-2; plate 14, figs. 4-5 



Leanchoilia superlata Walcott, 1912. Smithsonian Misc. Coll., vol. 57, p. 170, 

 pi. 31, fig. 6. 



Original description. — " Body elongate, with clearly defined head 

 shield and nine strong body segments up to the point where the 



