754 Retrospective Criticism. 



Chelifer cancroldes, a Lobster-like Insect^ parasitic on the 

 Common House-fly (Mwsca domestica L.). — As the gentlemen 

 who have so obUgingly answered (Vol. IV. p. 283, 284. 479.) 

 my query (Vol. IV. p. 94.), partly seem to think that the fact 

 of this insect's attaching itself to the fly's leg was accidental, I 

 have now to state that on the 17th of last month (July, 1832) 

 I saw a similar insect in a similar situation. I have erred, in 

 Vol. VI. p. 94., in calling the fly ilfusca carnaria ; it was the 

 M, domestica, or common house-fly. As I have in the course 

 of a few years thrice captured this insect when attached to the 

 leg of the house-fly, there can be but little doubt that it is a 

 parasitical insect, and exists by extracting the juices of the 

 fly. — O. Clapton^ August 30. 1832. 



Kirby and Spence mention {Introd.^ vol.iv. p. 229.) that the 

 Chelifer cancrbides " occasionally is parasitic upon flies, espe- 

 cially the bluebottle fly (Musca vomitoria). They adhere to 

 it very pertinaciously under the wings ; and, if you attempt to 

 disturb them, they run backwards, forwards, or sideways, with 

 equal facility." — J". Z). 



The Flying Leech (Vol.11, p. 368.) mentioned by Heber is 

 not peculiar to Ceylon, but is almost equally common and 

 noxious, during the rains, in the mountain jungles of the Ma- 

 labar coast on the continent of India. I never saw them 

 attempt to spring ; but they certainly (I speak from expe- 

 rience) contrive to fix themselves most dexterously on the legs 

 of men and horses, even when moving on at a smart pace ; 

 their bites often occasion very bad ulcers. For " Canely " 

 read " Candy." —A Subscriber. Vale of Alford, Sept. 28. 1832. 

 L'he Blood-red Zoophytes appear iiig in patches in the mud of 

 the canal at Bury St. Edmunds (see p. 387.) are no unusual 

 occurrences. I recollect having been taught^ when a very 

 little boy, to amuse myself by observing these creatures ; and 

 gently agitating the water, or shaking the earth, in order to 

 make them retire beneath the mud and disappear. The ani- 

 mal is very common, and may be met with, as J. D. observes, 

 in almost any situation suitable to its nature and habits. It 

 might be worth while to give a figure of it in your Magazine, 

 together with its name, and a more full description. — W. T. 

 Bree. Allesley Rectory^ May 10. 1832. 



For these we shall feel grateful to any correspondent, and 

 will publish them with pleasure. This animal (for a creature 

 so sensitive should not be called a zoophyte) is profusely 

 abundant in the mud on the margins of the Thames, at least 

 I found it so beside Cheyne Walk, Chelsea, in the rainless 

 evening of the otherwise rainy day, August 5. 1832. Cheyne 

 Walk is elevated 6 ft., and in some places more, above the 



