Royal Microscopical Society. 5 



that I could not dislodge them except in a rotary fashion, and I 

 was obliged at last to cover with a thin piece of glass and draw 

 them from the dorsal aspect under Powell's |th (immersion front). 



It is with some hesitation I record these notes in opposition to 

 the opinions of such accurate observers as Dujardin, Professor 

 Westwood, and Mr. Tatem. It is only from reading Mr. Tatem's 

 paper that I gather that his Acarelline forms are similar to Pro- 

 fessor Westwood's, and in both the examples he gives I doubt the 

 four-legged characteristics. Also, the prominence of what seem to 

 me to be the reproductive organs conveys to my mind the notion 

 that the Acarellus or Hypopus is an adult, not a larval, form. 

 Having been unable, however, to see these parts in life to my 

 satisfaction, I cannot make a drawing of them ; and the structure 

 of the tubular mouth, with the two terminal setae, prevents my 

 associating it in any degree with the nippers of Gamasus. In one 

 mounted specimen of Hypopus, I observed lately a curious disten- 

 sion of the end of the rostrum, reminding one of the lips of the 

 blow-fly, as if this organ were used for suction. 



Perhaps these notes may induce others to communicate facts in 

 then* experience in support or otherwise of my theory, and this 

 shall be my apology for intruding my remarks on the subject. 



When drawing the living Rypopus (Muscse) under the micro- 

 scope (|th objective), I could not help noticing the beauty of the 

 anterior pair of legs, and the remarkable spoon-shaped tenent hair 

 at the extremities. Its delicacy would I think quite render this 

 hair (or pulvillus) invisible in a mounted specimen. I could only 

 see one claw on each foot, but from the position of that member in 

 the anterior pair of legs, desperately holding on to the glass by 

 means of the tenent hair, a second claw might have been hidden 

 from view. 



Having seen Mr. Tatem's slides within the last few days, I 

 have altered my opinions as to the identity of the respective 

 creatures somewhat. His A. Muscse is different from mine, and is 

 probably a new species. His A. PuUcis confirms me in the sus- 

 picion expressed in a preceding note that it is an old acquaintance 

 of mine, and the bleached appearance of both specimens makes me 

 think more than ever that the potash treatment has had a very 

 injurious effect, and hidden delicate structure from view. In the 

 present state of the specimens I willingly lend my testimony to 

 the accuracy of Mr. Tatem's figures of them. 



Additional Note. 



November 13, 1873. 



I find, on comparing notes with Dr. Gray and others, that the 

 Acarelline form, called by Mr. Tatem A. Muscse, is by no means un- 



