56 SUMMARY OF CURRENT RESEARCHES RELATING TO 



hermit-crab with understanding what it does, " yet, assuming that the 

 remarkable behaviour of the hermit is due to instinct — that is, to an 

 'inherited combination of reflexes' which have been so brought to- 

 gether by the nervous system that the behaviour has become fixed and 

 adaptive in the species — it is extremely difficult to conceive how it has 

 acquired these habits." J. A. T. 



Arctic Decapods. — Arvid R. Molander {Arkiv f. Zool, 1914, 9, 

 1 pi.). A synopsis is given of the species of &pirontocaris^ and an 

 account of ^S'. recurvirostris sp. n., with a long rostrum sharply bent, with 

 its upper edge dentated, aud with the base free from spines over the 

 orbits. A hermit-crab, Eupagurus ])orceUanus sp. n., from the Behring 

 Sea, is marked by the completely smooth surface of the carpopodite and 

 propodite of the right forceps. Both these joints are strongly developed, 

 and the propodite is rectangular. J. A. T. 



Variability of Potamon edule. — A. Matteotti {Bull. Soc. Entomol. 

 Ital.f 1919, 50, 12-17, 2 figs.). A study of the variations in this 

 Crustacean as regards the dimensions and shape of the abdomen and the 

 characters of the third pair of maxillipedes. A distinction is drawn 

 between those connected with the age of the animal and those which are 

 true variations. J. A. T. 



New Species of Lernseopoda. — W. H. Leigh-Sharpe {Parasitology, 

 1919, 11, 256-66, 7 figs.). A description of L. nmstelicola sp. n., from 

 the smooth hound {Mustehis vulgaris). Only the female was obtained 

 Among the specific characters the following may be noted : cephalo 

 thorax pigmented with black dots ; proximal end of second maxillee 

 swollen; ovisacs short (4 mm., about two-thirds length of trunk) 

 abdominal appendages short (1 mm., about one-sixth length of trunk) ; 

 the base of the mandible bears a hooked projection on its inner side 

 The new species is compared with L. scgllicola, L. galei, and L. glohosa 

 Strange tumour-like growths from the cephalothorax* of L. scyllicola are 

 described, and a detailed account is given of the antennse of this species, 

 which bear what may be photo-receptors. These also occur iu L. galei 

 and L. mustelicola, but apparently not in L. globosa, which lives in 

 darkness. J. A. T. 



Annulata. 



Stomodseum of Lumbricidae — J. J. Menzi {Revue Suisse Zool., 

 1919, 27, 405-76, 2 pi., 13 figs'.). The stomodseum begins as a narrow 

 blind ectodermic tubule, with which the endoderm has no communication. 

 It grows back to the fourth segment, and histolysis occurs at the junction 

 of ectoderm and endoderm. A muscular cushion appears dorsal to the 

 stomodaeum, and is the first hint of the future pharynx, which is almost 

 certainly ectodermic in origin. The stomodaeum shows at first a 

 continuous internal ciliation, but this embryonic character disappears 

 and the cilia are replaced by a cuticle. The pharynx as it grows extends 

 as far as the sixth segment. There is general agreement that an ecto- 

 dermic invagination forms the mouth cavity in the regenerative process ; 



