366 SUMMARY OF CURRENT RESEARCHES RELATING TO 



in his comparisons, the Julidse in view, as some other Chilognaths have 

 a fusiform body. He doubts the accuracy of the statement that the head 

 appendages are carried on a single segment. The legs are a little 

 longer than in the Lysioi)etalid0e, and several of the characters indi- 

 cated are to be found in them also. Owing to the possession of 

 spinulate spines the fossils have a somewhat remarkable appearance, 

 but an approach to them is probably to be found in the barbed setao 

 on the segments of the embryo Strongylosoma, and in Polyxenus 

 fascintus. Dr. Packard thinks that the fossils form a group nearly 

 equivalent to the Lysiopetalidae, but below them. They are truly of 

 an ancient type, as is shown by the retention and enlargement of the 

 spiny setfe which occur in embryonic and larval Chilognaths, and by 

 the presence of a pair of spiracles on each segment (and not on alter- 

 nate ones, as in Chilognaths and ChilopodsJ. The characters of their 

 appendages are in keeping with this view. The legs would appear to 

 have had sharp claws, and there is no evidence to justify us in thinking 

 that they were swimming organs. 



The peculiar organs regarded by Scudder as supports for branchiae 

 are, in Packard's opinion, suggestive of this idea, and "it is to be 

 hoped that fossils will be discovered, with remains of the branchi© 

 themselves ; though it is hard to see how they could have been 

 associated with such large spiracles." Dr. Packard would divide the 

 order of Chilognatha into two sub-orders, one of the Archipolypoda 

 and the other of Chilognatha vera. In the latter the possession by each 

 segment of two pairs of legs is a secondary and acquired character. 

 A parallel may be found in the Phyllopod Crustacea, where " from two 

 to six pairs of legs in post-larval life arise from a single segment." 



Anatomy and Development of Peripatus Capensis.* — Prof. F. 

 M. Balfour's memoir on this species (a preliminary note of the em- 

 bryological portion having already api:)eared j") is now published, 

 edited by Prof. H. N. Moseley and Mr. A. Sedgwick, and illustrated 

 by eight beautifully executed plates. 



The more important facts of the early development of Peripatus 

 Capensis are as follows:—!. The greater part of the mesoblast is 

 developed from the walls of the archenteron. 2. The embryonic 

 mouth and anus are derived from the respective ends of the original 

 blastopore, the middle part of the blastopore closing up. 3. The 

 embryonic mouth almost certainly becomes the adult mouth, i.e. the 

 aperture leading from the buccal cavity into the pharynx, the two 

 being in the same position. The embryonic anus is in front of the 

 position of the adult anus, but in all i:)robability shifts back and 

 persists as the adult anus. 4. The anterior pair of mesoblastic 

 somites gives rise to the swellings of the i)re-oral lobes and to the 

 mesoblast of the head. 



It is intended that the present memoir should be followed by 

 others, comprising a complete account of all the species of the genus 

 Peripatus. 



* Quart. Journ. Micr. Sci., xxiii. (1883) pp. 213-.50 (8 pis.). 

 ■)• See thi.s Jonmal, nnte, p. .52. 



