790 REPORT— 1892. 



and floor of mouth, and a functional pronephros. The testes of a specimen of 

 Peti'omyzon planere described were stated to be hermaphrodite, in that here and 

 there in the testis single ova could be found. A section of such a testis with ova 

 was exhibited. 



12. On the SJceleton and Teeth of the Ausiraliaii Bugong} 

 By Professor G. B, Howes and J. Harrison. 



The authors showed that the vertebral epiphyses are more fully developed than 

 Albrecht has suspected, and that they appear late and rapidly ankylose with the 

 centra — a feature of especial interest, in view of Lefevre's alleged discovery of fully 

 developed epiphyses in HaUtheriuni Schinzi and Metaxythermm. On comparison 

 with the Cetacea, they sought to associate the reduction of the epiphyses with 

 adaptation to an aquatic existence. 



In dealing with the limb-skeleton, they described a longitudinal cleavage of 

 the phalanges, akin to that recorded by Kiikenthal for the Cetacea. The only 

 structures observed which were at all comparable to supernumerary phalanges were 

 derivatives of the terminal (ungual) ones, arising proximally ; and the observa- 

 tions lend no support to Kukenthal's view that supernumerary phalanges are 

 epiphysial in origin. 



The first upper incisor and the four lower ones of either side were shown to 

 have milk predecessors, which are early absorbed. Five teeth were shown to be 

 present on either side of the sympliysial region of each mandibular ramus of 

 Manatus, the fifth one being claimed as a canine ; and, in this animal, the 

 authors described milk predecessors to the two anterior pairs of mandibular cheek 

 teeth. The authors finally discussed tlie bearings of the facts upon the inter- 

 relationships and affinities of the Sirenia, for whose presumed incisors a numerical 

 parallel alone exists in the Marsupialia and Soricidse. 



13. Can Spiders Prognosticate Weatlier Changes ? 

 By Dr. M'COOK. 



14, Some Notes on Marine and Fresh Water Chironomus. 

 By G. SwAlNSON. 



15. The Earthtvorms of Great Britain. 

 By the Rev. Hilderic Friend, F.L.S. 



'We are indebted to the lamented Charles Darwin for any enthusiasm which has 

 been aroused among the pubHc in the subject of earthworms. The angler, how- 

 ever, was the pioneer student of terrestrial annelids, and to those who use the rod 

 ■we owe most of our popular names for earthworms. The first and only list yet 

 published in England appeared in 18G5, though many able monographs have 

 appeared on the Continent. In 1881 Darwin assumed the existence of eight or ten 

 .species of earthworms in England, and I have now to report the progress which 

 has been made in the subject since the publication of ' Vegetable Mould.' In 

 former times all our indigenous worms were ranged under the simple genus 

 Lximbricus, but in 1873 Eisen showed that they really belonged to four different 

 genera. He named them Lumbricus, Allolohophora, Allurus, and Dendrohfcna, but 

 the_ latter term has fallen into disuse, though I hope to show the wisdom of 

 reviving it for the true tree worms. The genus Lumbricus, tiH understood since 

 Eisen's time, first claims attention. It is distinguished by the ' mortise and tenon ' 

 arrangement of the head, the distribution of the setae in four couples, the indi- 



' Apropos of a Report by the Authors, upon the Sirenia collected by Professor A. C. 

 Iladdon in the Torres Stiaits, to be shortly published in the Traiu. lioy. Dublin Soc. 



