1646 the voyage of h.m.s. challenger. 



1887. Holm, Th. 



Beretning om de paa Fylla's Togt i 1884 foretagne zoologisehe Unders0gelser i 

 Gnzfnland; Meddelelser fra Gr0nland, B. viii, pp. 153-171. 



This work is mentioned by Hansen in his " Malacostraca marina Groenlandiae oecidentalis," 

 p. 216. Professor Hansen had himself supplied the lists of Crustacea for it, and in his own 

 work takes the opportunity of correcting two names, Monoculodes norvegicus, Boeck 

 (pp. 167 and 155), a wrong determination for Monoculodes simplex, n. sp., and CapreUa 

 dubia, Hansen (pp. 168, 157, and 158), which he now describes as " Capr. microtuberculata, 

 G. 0. Sars, var. spinigera." 



1887. KOEHLER, R. 



Beckerches sur la structure du cerveau du Gammarus pulex. (Aus der 

 iiiternationalen Monatsschrift f. Anat. u. Fhys. 1887. Bd. IV. Heft. 1.) Avec 

 pi. I. 16 pages. Leipzig. 



Microtome sections in various directions through the head of Gammarus pulex are described and 

 figured. Since the upper antennae carry the olfactory cylinders, the nerves which run to 

 them are. called, by Bellonci's term, the olfactory nerves. Two groups of cells which 

 extend all along the dorsal face of the brain are designated the upper longitudinal bands ; 

 in these one cell is met with of considerable size (la cellule geante). The brain is 

 divided into three regions ; the upper including the group of the upper lobes and of the 

 optic ganglia with the cells annexed (cells of the upper bands, of the upper lobes, and 

 the nervous sheath of the optic ganglia), the middle including the median lobes with the 

 median and central cells ; the lower including the group of the olfactory lobes and ganglia. 

 The middle region has its two lobes united by a commissural band which separates them 

 from the upper region. In the central region there is a small empty space. 



In comparing his own results with Bellonci's description of the brain of Sphxroma serratum 

 Dr. Koehler finds that the four cellular groups attached to the upper lobes of the brain of 

 the Isopod (the first containing the giant-cell), have their equivalents in Gammarus, but 

 with less distinctness in the grouping. The optic ganglion is constituted by two distinct 

 lobes, but has not the hinder reticulated swelling, which Bellonci found well developed in 

 Idotea and rudimentary in Sphxroma. As in the Isopods, the nerve destined for the 

 antenna which carries the olfactory cylinders rises in an olfactory lobe to which is annexed 

 a swelling with special structure, besides various cellular groups. The nerve of the lower 

 antenna springs, as in the Sphasroma, from the oesophageal commissure, but the group of 

 cells connected with it at its origin is in Gammarus above instead of below the point of 

 origin of the nerve. The bundles of fibrillae coming from the olfactory region form a 

 chiasina in the central region of the brain. These bundles penetrate into the upper, that 

 is to say, the optic region, presenting an incomplete intercrossing, since certain vertical 

 fibrillar pass directly into the optic region of the same side. 



The brain of Gammarus, therefore, Dr. Koehler says, appears to come closer to that of the 

 Isopods than to that of the Phronimidaa as described by Claus. " Ce savant a reconnu 

 aussi chez les Phronimides un chiasma central, mais la signification de ce chiasma comme 

 entrecroisement de faisceaux optico-olfactifs, est moins nette que chez les Isopodes et le 

 Gammarus, puisque le nerf olfactif ne parait pas prendre son origine chez les Phronimides 

 dans la menie region centrale que chez les autres Edriophtalmes etudies. La region que 

 j'ai decrite sous le nom de region moyenue ne parait pas exister chez les Phronimides. Le 



