V 



782 



iiEPOUT — 1884. 



ifH 



m 



1 1 



of which the sliell surface is covered, but between the bases of tliese. The niCTa! i- 



f lores and mici-oporcs lodginjr the orf^ans cf touch are arranged in vertical parallii 

 iiies with great regularity, the large pores occurring at intervals the lines of 

 smaller pores. The eyes are present in enormous numbers, the anterior shell aluin' 

 bearing more than ;),00(), and the entire eight shells more than 11,500. 



In Tonirin inannoi'(tta the eyes are arranged in single sti'aight radiatino' vown 

 o:i the anterior and posterior shell. On each lattn'al area of the intermediatr 

 shells there are from two to four similar rows of eyes. In Onithochitou the evi's 

 nre disposed somewhat similarly. 



In the genus Chiton, eyes a])])ear to he entirely absent, though the touch or.Mii 

 of two sizes and corresponding pores are present. In Molpalia, Maugina, Lorim 

 and Ischnochiton, I have as yet detected no eyes. In Cliitimellus there ariMii 

 eyes, and the supply of touch organs is scanty and conlined to the margins of th> 

 tegmenta. 



The arrangement and structure of the eyes and organs of tiMn-h will prnbaUv 

 be of great value in the classification of tlie Chitonidai, which has hitherto jmivtd 

 ,so difficult a problem. 



No traces of any structures resembling the eyes and touch organs of tlie f'liiti- 

 nidoe can be detected in the shells of Patella or allied genera. The tegnientarv 

 ]iart of the sh<'!ls of this group a])])ears to bo something sui yencris, entirely unre- 

 presented in other Mollusca. Its principal function seems to be to act as a secure 

 protection to a most extensive and complicated sensory apparatus which in the 

 Chitonidaj takes the place of the ordinary organs of vision and touch present in other 

 odontophora, and fully accounts pliysiologically for the absence of these latter in 

 them. 



Dr. W. B. Carpenter observed the perforate structure of the tegmentum in 

 Chiton, though he did not examine the nature of the contained soft network. The 

 late Dr. Gray, in his well-known paper on the structure of Chitons, recognised thi- 

 fact that the tegmentum in t)ie ChitonidtB is something ;«'««//«?• to the shells of this 

 family. 



Since the above was written, the author had his attention drawn to a memoir 

 by Dr. W. Marshall, in which the tul^ulate structure of the tegmentum of the shells 

 of Chitonida> is descrilied, and to papers by J. F. Van Bemmelen, in which thi' 

 papilliform bodies which occupy these in Chiton mari/iiinfn.'t are described and 

 f.gured. These memoirs are referred to fully in an extended and illustrated memoir 

 on the present subject, published in the ' Quarterly .Tournal of Microscopical 

 Science,' for January 18S5. The eyes appear to have entirely escaped the obser- 

 vation of naturalists hitherto. 





10, 0)1 the Structure and Arranrjement of the Feathers in the Dodo. 

 B>j Professor H. N. Moseley, LL.B., F.KS. 



Professiir Moseley's observations were made on the only existing specimen of 

 the skin of the bird, namely, that covering the head belonging to the Oxfoni 

 University Museum. The feathers differ from those in all other birds in beinsr 

 arranged in groups of three. Tliis peculiarity is shown in the well-known old oil 

 paintings of the Dodo. The homologues of the lateral feathers in each 'n'oupof 

 tliree are to be sought in the two minute filo- plumes which spring from the sheath 

 of each feather at its base, one on either side in modern pigeons. An illustrated 

 paper on this subject will be communicated to the Zoological Societv in the sprinj; 

 of 1885. ^ 



11. On the Pref>ence in the Bnteropneusfca of a structure comparable w'A 

 the Notochord of the Chordata. By William Bateson. 



12. A Contrihutinn to our Knowledge of the Phytopti. 

 By Professor P. McMurkick. 



L^ 



ita^^ 



