28 Mr. J. Ball on Odontites rubra, with notice of a new species. 



DEAR Sir, Tavern Street, Ipswich, Suffolk. 



We have in our Wet Salt-water Dock a species of Hydroid 

 Polype which I have not met with in any publication that I have 

 had an opportunity of referring to. It differs materially from the 

 common species of our freshwater ponds in its body being less 

 capable of extension, and in its having when mature from six- 

 teen to twenty-one extensile tentacles around its disc, in the cen- 

 tre of which, and rising considerably above the surface, when 

 protruded, is a singularly and beautifully organized four-lobed 

 mouth : the instant adaptation of its opening to the incurving 

 tentacles, and its effective closing thereon when they are intro- 

 duced into the cavity, are operations of the most interesting cha- 

 racter. Around the base of the mouth, and equidistant from each 

 other, are four oviform orifices, corresponding with the four pro- 

 jecting lobes of the mouth and extending to the base of the 

 nearest tentacle, giving to the disc somewhat the appearance of 

 a flower with a four-cleft corolla. 



The incipient gemmation of this polype is spurlike and acute, 

 upon which the young polype is formed : in some instances this 

 spur or offshoot terminates in a little bulb, presenting the ap- 

 pearance of a simple pistil of a plant having its stigma at the 

 extremity and the germen at its base : upon offshoots of this 

 latter form we have not at present noticed any young. 



I observed, previous to the death of this little creature, that 

 the tentacles became incurved, and, at such times, substances 

 floating over the orifice of the disc obtained a rotatory motion as 

 if operated upon by cilia. 



Believe me to remain, &c, 



Edwin Giles. 



IV. — On Odontites rubra, Pers., and the allied forms, including 

 a notice of a new species. By John Ball, M.R.I.A. 



This attempt to clear up the confusion which seems to exist as 

 to the forms of the group of plants which were known to the 

 older botanists under the name of Euphrasia Odontites, L., is 

 subject to great disadvantage, being chiefly founded upon the 

 examination of dried specimens, from which it is very difficult 

 to determine the true form and structure of the corolla and 

 anthers, the organs from which the most important specific cha- 

 racters are derived. I may observe in the first place, that some 

 of the characters used by authors appear to me altogether falla- 

 cious ; thus I find the relative length of the floral leaves, and the 

 breadth of the segments of the lower lip of the corofla to vary in 

 all the forms of this group. I proceed to point out by brief 

 diagnostic characters the forms with which I am acquainted. 



