CORRESPONDENCE. 205 



explained, the creature having been obtained by Mr. Stubbs from 

 the Brighton Aquarium, and found to be parasitic on the Cetacea. 

 The order contains but one family, but several genera — some 

 British, others exotic, but all exclusively marine. The specimen 

 exhibited was furnished with eight legs surmounted with claws. 

 Head tubular, in the form of a beak or proboscis. The abdomen 

 rudimentary, with a very remarkable digestive cavity extending 

 into the legs of the creature. These ramifications of the alimen- 

 tary canal, however, appear to serve all the purposes of circulatory, 

 respiratory, and chyliferous systems as in higher animals. Another 

 slide was passed round the table from the order Scorpionidce^ and 

 consisted of a fine Scorpion obtained from the shores of the 

 Mediterranean. The body was of an elongated oval shape, 

 covered with a horny integument. The abdomen united to the 

 thorax, and consisting of 1 2 segments, five of the latter becoming 

 narrower and forming the tail, which ends in a sharp curved sting. 

 The poison which flows from this formidable weapon appears to be 

 carried through two ducts to ten orifices near the point of the 

 sting. The poison of the Scorpion is more or less venomous, 

 depending on the age of the creature and the season of the year, 

 and certainly upon the health or otherwise of the victim. — At the 

 close of the paper, a discussion ensued upon the nature and effects 

 of the poison. — Dr. Hensley tendered the thanks of the Society to 

 Mr. Stubbs for introducing so interesting a subject. — Mr. Pumphrey 

 exhibited a specimen of fresh-water Algae (Batrachospermiun), 

 which had been introduced into a stream in his garden, and 

 appeared to be well established. 



Correapon&ence* 



The Editors do not hold themselves responsible for the opinions or 

 statements of their Correspondents. 



Bacillaria Paradoxa (p. 158). 

 To the Editor of " The lour?ial of the Postal Microscopical Society:' 

 Sir,— 



Many years ago I found this Diatom in the ditches inter- 

 secting swampy meadows on both sides of the river just above the 

 town of Stafford, and communicated the fact to Professor 

 Henfrey's "Botanical Gazette," 1851, p. 135. 



