"Sli.MarrilTa'l PROCEEDINGS OF SOCIETIES. 267 



sliell of a fresh specimen in dilute acid ; and also slides of Nodosarince 

 and a small Lingidina. 



The siliceous skeleton of a polycystine form of Eadiolaria of fre- 

 quent occurrence at considerable depths, was shown in Dr. Carpenter's 

 collection ; and a slide of Eadiolariae taken alive on the surface of the 

 sea in the neighbourhood of Shetland, where they float in masses, 

 mingled with Entomostraca, which are known to the fishermen as 

 " madre," and are said to furnish food to the herring shoals. 



A slide of the siliceous skeleton of Aphroccdlistes Bocageii, " first 

 discovered by Dr. Perceval Wright off the coast of Cornwall, and 

 since found at great depths at the mouth of the Bristol Channel, was 

 shown ; and likewise the interesting crinoid, BMzocrinus lofotensis, 

 first discovered by Professor Sars, at a depth of about 300 fathoms, near 

 the Loffoden Islands ; and since met with in the ' Lightning ' and 

 ' Porcupine ' Expeditions, at various depths down to 2000 fathoms ; 

 found also in the Gulf of Mexico. This crinoid belongs to the 

 Apiocrinites, of which the pear-shaped fossil of the Bradford clay is a 

 characteristic representative." 



The Deep-Sea annelids were represented by tubes ; " some built 

 up of Globigerinse ; others of cemented sand-grains ; while others 

 have a coloured internal layer of animal substance, which acts as a 

 foil to the sand-grains that are attached to its outer surface." 



Dr. Carpenter brought a beautiful series of drawings, illustratiug 

 the objects displayed, and others that were foimd in the Deep-Sea 

 Dredgings. Mr. Henry Lee made the arrangements and assisted Dr. 

 Carpenter in this part of the exhibition. 



Neiv Instruments, Objectives, &c. — Messrs. Powell and Lealand ex- 

 hibited a ^th and ^i\i. objective on the immersion j)rincij)le, both 

 worked upon new curves. The former was shown in action u2)on the 

 test Podura scale {Lepidocyrtus curvicollis) ; and the latter upon the 

 Navicida rhomhoides. These new lenses differ somewhat in the cha- 

 racter of their definition from those previously used by the same firm. 

 They are more perfectly achromatic, not only without sacrificing, but 

 with an addition to sharpness of definition, and give a brilliant field 

 without the glare so common in immersion objectives. These ob- 

 jectives are fiu-nished with fronts for diy use. 



Messrs, E. and J. Beck exhibited an immersion ith, showing the 

 Podura markings very distinctly, characterized by the well-known 

 appearances in the drawings of the late Eichard Beck, and which 

 microscopists have accepted as tests. 



Mr. Crouch exhibited an immersion |th, working well upon 

 P. angulatum, and belonging to his new series of objectives. 



The most decided novelty was shown by Mr. Holmes, who ex- 

 hibited four binocular microscopes, each difiering in mechanical 

 arrangements ; but all upon a hitherto untried optical princij)le of 

 dividing the objective by vertical section into two equal and corre- 

 sponding halves. The powers employed were one inch. Each tube 

 of the binocular was equally illmuinated, and the definition sharp. 

 These instruments will be brought before the notice of the Society at 

 its next meeting. 



