52 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of the cones ; hence the beginning of the division of the eye into two 

 parts. The diminution in the amount of pigment again has the result 

 of making the eye more susceptible to movements. The reason for the 

 modification in the Polyphemidae is to be sought in their adaptation to* 

 a predatory life, and to their existence in water of considerable depth. 

 Their eyes are adapted less for the perception of form than for the 

 perception of movement in dim light. 



Arctic Amphipods.* — Ed. Chevreux gives an account of some in- 

 teresting Amphipods found during the last voyage of the ' Princess 

 Alice.' Good results were obtained by the use of the tow-net at great 

 depths. Among other forms one specimen of Euryporeia gryllus was 

 obtained from a petrel. This interesting giant Amphipod has been 

 taken on many occasions by the ' Princess Alice,' and at all depths 

 from the surface to one of 5310 metres. A new giant form reaching 

 a length of 140 mm., was found at a depth of 5285 metres, and is 

 described as Alicella gigantea g. et sp. n. A full account of the cha- 

 racteristics of this new form are given. Two specimens only were 

 found, both females, but of very unequal size. 



Distribution of Cirripedia.j — Dr. W. Weltner gives an account of 

 the Cirripedes taken by Schauinsland's Expedition. None of the species 

 are new, but in some cases new localities are noted for already described 

 species. Weltner finds that, apart from pelagic species, only two Cirri- 

 pedes are common to the Arctic and Antarctic regions, and are yet 

 absent from intervening regions. Of these, one (Scalpellulum velutinuiny 

 is a deep-sea form, the other (Balanus porcaius) lives from low-tide mark 

 down to the greatest depths. On the whole the Cirripedes offer no 

 support to the bipolar hypothesis. 



Fresh-water Copepoda.J — Herr Carl van Douwe records Biaptomus 

 denticornis Wierzejskii in the neighbourhood of Peissenberg, Bavaria, 

 in upland ponds. This is the first German record of this brilliantly 

 coloured Crustacean, and confirms the previously expressed opinion that 

 it is confined to ponds at a considerable height above the sea-level 

 (about 740 m. in this case). In the Bavarian ponds the number of in- 

 dividuals was large, and they constituted almost exclusively the limno- 

 plankton of the area. 



Harpacticid Appendages.§ — Herr C. van Douwe has some notes on 

 the fifth pair of appendages in Copepods, which, especially in their 

 rudimentary form in Harpacticida?, are credited with great specific con- 

 stancy and consequent taxononric value. He cites in illustration the 

 differences in the number of spines on this appendage in Canthocamptus 

 northumbricus Brady, and refers to other cases. 



New Harpacticid8e.|| — A. Graeter notes that, while further research 

 tends to reduce the number of species of Cyclops (from 150 to about 

 23), the reverse is true of Harpacticidae. He records from the Val 

 Piora Canthocamptus cuspidatus, also known from the Rhasticon, and 



* Bull. Soc. Zool. France, xxiv. (1899) pp. 147-58 (11 figs.). 



t Zool. Jahrb., xii. (1899) pp. 441-7. J Zool. Anzeig., xxii. (1899) pp. 387-8. 



§ Tom. cit, pp. 447-50. i; Rev. Suisse Zool., vi. (1899) pp. 365-7 (1 pi.). 



