ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 69 



genital ducts of Arthropods are also modified nepbridia. He states 

 that he has recently ascertained that the blood-system in the larger 

 Artbropoda is altogether distinct from the general system of lacunas 

 of the connective tissue. 



6. Crustacea. 



Blind BrachyuroTis Crustacean.* — Mr. J. Wood-Mason states that 

 four species of Brachyura were di-edged in the Bay of Bengal from 

 depths exceeding 100 fathoms during the past season by H.M.'s Indian 

 Marine Survey steamer ' Investigator.' They belong to the genera 

 Amafhia, Ethusa, Enceplialoides (n. gen. allied to CoUodes Stimpson), 

 and Lyreidus, of which the last-named (L. Channeri) is especially 

 interesting on account of the rudimentary condition of the eyes. 



These organs are unequally reduced, the cornea of the left being 

 of the normal form and extent, but opaque and devoid of all traces of 

 facets, as in Munidopsis, OrophorJiynchus, Nephropsis, and other blind 

 forms of the deep sea, while that of the right is entirely aborted, its 

 place being only indicated by a small smooth spot marked out by the 

 transparence of a lead-coloured pigment similar to that which is seen 

 through the integument around the base of the left eye. This 

 interesting brachyuran — which is at once distinguished from the 

 Japanese and American species by having the anterolateral margin 

 of the carapace armed with two pairs of long and slender spines — were 

 trawled up from a depth of 285-405 fathoms. 



Notes on the Stomatopoda. f — Dr. W. K. Brooks traced the 

 development of the larvae of Squilla empusa, and Lysiosquilla sp., by 

 means of the general appearance of various stages, not being able to 

 obtain the eggs nor to keep the younger larvae alive in confinement. 



The youngest Lysiosquilla was in the stage of "Clans' larva"; 

 this is followed by the Erichthus stage, which he traced into a 

 young Lysiosquilla. Several facts in the natui'al history of these forms 

 are given. Squilla produces a striduating noise by rubbing the 

 serrated spine of the swimmeret across the serrated ridge of the telson. 



Structure of the Brain of Sessile-eyed Criistacea.+ — Dr. A. S. 

 Packard describes the brain and other nerve-centres in the head of 

 Asellus communis and the eyeless Cecidotsea siygia. The ganglion-cells 

 have not, as in the brain of the lobster, a simple nucleus, but ten to 

 twenty nuclei; they appear to be entirely unipolar; the "Punktsub- 

 stanz " of Leydig, which Dr. Packard proposes to call the myeloid 

 substance, is not, as in many, difterentiated into distinct spherical 

 masses, and in this respect there is a wide difterence between the 

 brains of Decapoda and Hedriophthalmata. All the ganglion-cells 

 appear to give rise to fibres, some of which pass directly through or 

 above or around the myeloid substance of the cerebral lobes and 

 form the commissures. 



Though far less complicated than that of the Decapoda, the brain 



* Proc. Asiatic Soc. Bengal, viii. (1885) p. 104. 



t Johus-Hopkins Univ. Circ, v. (1885) p, 10. 



J Mem. Nat. Acad. Sci., iii. (1885) 14 pp. (5 pis.). 



