ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 275 



in the pericardial cavity decreases. The contraction of the heart in 

 Pholcus phalangiodes was seen to be connected with a diminution of 

 pressure in the pericardial cavity and in the pulmonary vein, thus 

 influencing the lungs. The circulation of blood in the lungs is a 

 passive consequence of the systole of the heart. The blood-pressure of 

 the peripulmonary lacuna, which always exceeds the atmospheric pressure, 

 keeps the air-cavities of the lungs and the cuticular portions of the 

 lamellffi and of the vestibule compressed. Changes in the pressure due 

 to palpitations of the heart cause the air-cavities to become alternately 

 smaller and larger. The elasticity of the cuticular portions of the 

 lamella? is the intermediate factor in the movements of air in the lungs. 

 In special cases the movements of the muscles of the body may help. 



J. A. T. 

 New Pycnogonid. — T. Thomson Flynn {Papers and Proc. R. Soc. 

 Tasmania, 1911), 11-15, 1 pi.). Description of a male specimen of 

 Halosoma haswelU sp. n., found among the mussels on Shark Island, 

 New South Wales. The genus differs from Anoplodacfylus in the 

 particularly small size, the crowded nature of the crurigers (hollow ' 

 processes of the body wall to which the ambulatory legs are attached), 

 the tendency of the trunk segments towards coalescence, the feeble 

 development of the neck, the particular arrangement of the spines on 

 the legs, and the structure of the tarsus and propodus. J. A. T. 



5, Crustacea. 



Double-walled Sensory Setse in Oxyrhyncha. — ^R. Issel (PuM. 

 Staz. ZgoI. NapoU, 191^, 2, 147-58, 1 pi.). A study of sensory setae 

 with an outer and .an inner cuticular support, united by trabecule. In 

 Acanthonyx Ivmdatus, Pisa, Herhstia and Lissa the detailed architec- 

 ture is described. It may be that osmotic variations influencing the 

 outer layer affect the internal wall and the contained nerve through the 

 intermediation of the trabecule. The structures are peculiar to 

 Oxyrhyncha. J. A. T. 



Crustacea and Pantopods of Oresund, — W. Bjorck {Limds Univ. 

 ArssJcrift, 1915, 11, No. 7, 1-9S, 1 map). A description of the 

 Malacostraca and Pantopods from this area. The whole fauna is a 

 llacoma-commnnitj. The littoral forms are almost without exception 

 present in at least the west part of the Baltic, several extending far into 

 that area. The sub-littoral forms inhabit the deeper parts (20-50 m.) 

 of the Sound, and consist of forms which seldom (and as a rule only in 

 solitary specimens) are met with in the west part of the Baltic. The 

 species Diastylis rathMi and Michtheimysis mixta, which occur abun- 

 dantly, are exceptions to this statement. The sub-littoral fauna 

 inhabits for the most part the clay bottom, and may be classified as a 

 HapJoops-commxmi'ij . The composition of the fauna lends no support 

 to the hypothesis, advanced by Lqnnberg, of the persistence of an 

 Arctic character in the fauna of the Oresund. J. A. T. 



Crayfishes and Amphibolites. — Jean Couegnas {Arch. Zool 

 Exper., 1920, 59, Notes et Revue, No. 1, 11-13). In Limousin, a 



