ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 25 



deals with the three Italian species of Kcmmia. He also describes 

 Acropsopilis chilensis g. et sp. n., referred to a position among those 

 Opilionidae palpatores which have some characters of the Eupnoi and 

 many characters of the Dyspnoi. Another new form is Opilioacarus 

 platensis from South America, a mite belonging to the sub-order 

 Notostigmata. 



New Spider.* — Frank P. Smith describes Anglia hancockii g. et 

 sp. n. from Yarmouth. It has affinities with the Linyphiinae and the 

 Erigoninae, but the structure of the palpus and palpar organs leads the 

 author to refer it to the latter sub-family, of which it appears to be an 

 early type. 



Structure of Hydrachnid Eyes.f — P. Lang has investigated these in 

 Diplodontus despiciens, Curviceps carneus, and other species of different 

 genera. Hydrachnid eyes are single layered, not inverted ocelli, without 

 vitreous body or preretinal membrane. The retina cells are in the main 

 arranged in groups of two. Each cell differentiates a rhabdome element, 

 so that the rhabdomes are bipartite. Both the anterior ocelli are movable, 

 except in those cases where movement is prevented by the enveloping 

 chitinous capsule. In double eyes the posterior smaller visual body 

 moves passively with the others. The movement is effected by a muscle 

 attached to a horn-shaped lens continuation which is closely fastened to 

 the cuticula dorsally. No accommodation is brought about by the 

 movement, but only a change of direction of the visual axis, so that 

 new objects are projected upon the retina. Some comparisons are made 

 with the eyes of other Arthropods. 



«• Crustacea. 



Life-History of the Lobster.} — H. Chas. Williamson describes the 

 larval stages of Homarus vulgaris, with finely illustrated details as to 

 the appendages and branchiae. Some of the common variations of 

 the megalops are noted. The processes of moulting are discussed at 

 length, and there are many interesting notes on behaviour, spawning, 

 hatching, as well as statistics regarding rate of growth. 



The Genus Peneus.§ — A. Alcock gives a revision of this genus. 

 All the sections — genera or sub-genera — into which the old Fabrician 

 genus has gradually become split are tabulated and briefly defined, and 

 an attempt is made to sift all the species that have been described under 

 the name Peneus and to distribute them to their proper sections. The 

 paper contains further the diagnoses of nine new forms. 



Sense-Organ in a Schizopod.|| — R. Dohrn describes on the eye- 

 stalks of the Schizopod Eucopia a short funnel-shaped prolongation, 

 situated on the side turned towards the median plane of the animal. It 

 lies projecting over the eye. At the base there is a cell complex, bulb- 

 shaped, and immediately below this an oval heap of cells about the same 



* Journ. Quekett Mior. Club, 1905, pp. 247-50 (1 pi.), 

 t Zool. Jahrb. Abt. Anat., 1905, pp. 453-94 (2 pis.). 



j Fisbery Board for Scotland, 23rd Ann. Rep., part iii. (1905) pp. 65-107 (4 pis.). 

 § Ann. Mag. Nat. Hist., xcv. (1905) pp. 508-32. 

 || Zool. Anzeig., xxix. (1905) pp. 347-52. 



