511 



is closely united with the body-wall on all sides by very numerous 

 short strands of a soft yellowish-brown tissue. There is no evidence 

 of any communication between this chamber and the exterior, tho at 

 the smaller end there may have been an opening, at some earlier day. 

 There are no tentacles, pedicels or other evidences of a water vascular 

 system nor are there any muscles, nerves or sense-organs, so far as 

 macroscopic observations show, — The specimen is about 15 mm in 

 length and the greatest height is about the same. — The color is light 

 brown. 



This curious animal was dredged by the »Albatross« in 1588 

 fathoms of water off the Queen Charlotte Islands, on a bottom of ooze 

 and at a bottom temperature of 35,3° Fahr. It has been in alcohol for 

 some years and the inner tissues are very soft. There can be little 

 doubt that the specimen is a monstrosity; but of what? My own 

 opinion is that it is a holothurian, related to Sphaerothuria^ but the 

 spines and the »digestive tube« (?) are very much like those of an 

 Echinoid. — The most puzzling question to me is, how did an animal 

 with apparently no mouth or anus and no means of locomotion reach 

 such a considerable size ? 



Olivet, Mich., March 13, 1902. 



5. On a Pair of Ciliated Grooves in the Brain of the Ammocoete, appa- 

 rently serving to promote the Circulation of the Fluid in the Brain-cavity. 



By Arthur Dendy, Canterbury College New Zealand. 



(Communication made to the Royal Society, London.) 



iWith 6 figs.) 



eingeg. 4. April 1902. 



The peculiar and apparently hitherto undescribed structures which 

 form the subject of the present communication, were first discovered 

 in the course of an as yet unfinished investigation of the parietal 

 organs in the New Zealand Lamprey [Geotria australis). The Ammo- 

 coete of this interesting species is known to us only through two speci- 

 mens: one of these was briefly described by Kner in 1869 i; the other 

 was for many years in the Museum of the Otago University, Dunedin, 

 and was forwarded to me for investigation by the present curator. 

 Professor W. B. Benham, D.Sc, to whom I desire to express my 

 indebtedness for his great kindness. 



The specimen which I have thus had the opportunity of investi- 

 gating was labelled in the handwriting of the late Professor T. J. Par- 



1 Reise der Österreichischen Fregatte Novara um die Erde, Zoologie, 

 Bd.. 1, Fische, p. 421. 



