Notes on the Anatomy of Dinophilus. 



By 



Sidney F. Harmer, M.A., B.JSc, 



Fellow and Lecturer of King's College, Cambridge. 



With Plates IV and V. 



The anatomy of Dinophilus, a genus established by Oscar Schmidt 

 in 1848, has formed the subject of several memoirs, amongst which 

 attention must be specially called to the recent papers of Korschelt 

 (6), Repiachoff (12), and Weldon (13). A complete account of the 

 synonymy of the genus was given by t. G-raff* in 1882, whilst 

 Korschelt (7) has, within the last year or two, published a review of 

 the facts known with regard to the anatomy of the various species 

 of JDinophilus. Full references to the literature of the subject will 

 be found in v. Graff's monograph (loo. cit.) as well as in the memoirs 

 of Weldon (13) and Korschelt (6 and 7J. In view of the recent 

 appearance of the above-mentioned papers, it is unnecessary for me 

 either to give a complete list of references or to attempt any histori- 

 cal account of our knowledge of the genus. 



The animal which forms the subject of the present paper was 

 found at Plymoutht, and has been described as a new species, under 

 the name Dinophilus txniatus, at a meeting of the Cambridge 

 Philosophical Society. { 



D. tseniatus was found, in very great numbers, in rock-pools far 

 above low-water mark, during the latter end of March and the first, 

 half of April. It was unfortunately necessary to interrupt the 

 observations on April 18th, a day or two before which time it was 

 noticed that the*eggs which were being produced by the females 

 were rapidly developing. On returning to Plymouth on June 26th 

 no trace of the animal was discovered. Other observers, as Hallez 

 (4) and Weldon (13) have recorded the fact that the species of 

 Dinophilus which they have respectively described are only to be 

 found during the spring. 



* V. GrafE, L., Moiiographie der Tnrbellarien. I. Rhabdocoelida. Leipzig, 1882. p. 1. 



t Tlie study of the anatomy of Dinophilus was greatly facilitated by the excellence of 

 the arrangements of the Laboratory of the Marine Biological Association, to the Director 

 of which, Mr. G. C. Bourne, 1 desire to express my best thanks for the courtesy with which 

 I have been treated during my visits to Plymouth, 



J Proc. Camb. Pliilosoph. Soc, vol. vi, 1889. 



