232 J. H. ORTON. 



with active sperm and an unsuccessful artificial fertilization tried. It 

 is highly probable, however, that the species breeds a little later than 

 this time of the year, as specimens taken in early May and September 

 had only immature ova in the gonad, 



ON THY ONE RAPHANUS DUB. AND KOR. 



Nine specimens of Thyone raphanus Diib. and Kor. were taken at 

 various times between July, 1911, and July, 1912. These specimens 

 were captured, except in one case, in the fine-meshed dredge in muddy 

 sand or in muddy gravel in depths from about 12 to 30 fathoms. Four 

 specimens were taken on one occasion 1| to 2 miles S. of the Mewstone? 

 and on another one specimen 1| miles of? Yealm Point. Two were 

 obtained in July, 1911, about 3 miles S. of Rame Head, and two in May, 





Fig. 12. — Thyone raphamis. The body portion was drawn from the living animal and 

 the tentacles afterwards added from a preserved specimen (x f). 



1912, in a position 5 to 5| miles S. | E. of Rame Head. In the same 

 month one specimen was taken in the trawl on the inner portion of the 

 Rame-Eddystone trawling grounds. 



The specimens varied in size from 2*5 cms. long by 7 mms. wide at the 

 widest part to 6"2 cms. long by I'l cms. wide, the measurements being 

 taken from the preserved animals. Their general colour was of a creamy 

 white, and when obtained from the dredge they were bent in the form 

 of a U, In none of the specimens examined were ripe sexual products 

 found, hence it is likely that breeding occurs during the winter months. 

 The spicules from the skin, tube-feet, and tentacles agree closely with 

 those given by Diiben and Koren (14, Plate V, Figs. 49 to 55). There 

 are, however, some spicules with bosses arranged concentrically around 

 the foramina, but probably the Figures 50, 51, and 54 in the afore- 

 mentioned plate are an attempt to represent these bosses. The calcareous 



