ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 697 



the proboscis, and 8- jointed ; the false legs are weak, 10-jointed, with- 

 out denticulated spines, with the last four joints strongly curved, and 

 with a very small claw on the tenth joint. The legs are slender, with a 

 strong terminal claw without auxiliary claws. The lateral caeca of the 

 intestine penetrate to the fourth joint of the legs. Eggs are found in 

 the body and its lateral processes, but only in the proximal two joints 

 of the legs. The author also discusses the proboscis of Pycnogonids in 

 general. 



Ceylonese Pantopoda.* — G. H. Carpenter describes Phoxkhilus 

 mollis sp. n. and Nymphon longicaudatum sp. n. from Ceylon. It is 

 noted that both these species are remarkably poor in spiny or heavy 

 armature or clothing, as compared with other members of their genera. 



«• Crustacea. 



Affinities and Distribution of Cambarus.f- — A. E. Ortmann dis- 

 cusses the affinities of the species of Cambarus, grouping them under 

 four sub-genera according to the chief types of the sexual organs of the 

 male. The various species are reviewed from the point of view of their 

 distribution over the United States, and here amongst other points are 

 noted the following. Morphologically isolated species occupy isolated 

 stations, e.g. C. cubensis in Cuba ; C. shufeldti in Louisiana ; C. setosus 

 in Missouri (cave form). Closely allied species occupy neighbouring 

 areas ; this is evident in cases where groups of species occupy a certain 

 range, but represent each other in the different parts of this range. 

 More or less closely allied species, occupying the same or nearly the 

 same territory, are generally of different habits, e.g. C. virilis prefers 

 running water with stony bottom, while C. immunis is a pond and ditch 

 form. Very important drainage changes that have taken place in the 

 southern Appalachian system are clearly indicated by the distribution of 

 crayfishes. Identical or closely allied forms are found in separate 

 systems which formerly were united. This is illustrated by C. erkhso- 

 nianus, C. extraneus, etc. 



Sperm-receptacle of Cambarus.J — E. A. Andrews describes the 

 peculiar " annulus ventralis," or sperm-receptacle, found on the ventral 

 surface of the females of American crayfishes of the genus Cambarus, 

 and shows that its use forms so integral a part of the complex sexual 

 habits of the crayfishes that without it the eggs would not be fertilised. 

 It is an elevation of the areolar connective tissue full of blood, on the 

 ventral side beneath the nerve-cord, covered by a peculiar mass of exo- 

 skeleton, and inclosing a peculiarly bent trumpet-shaped cavity. It 

 receives the spermatozoa from the male, and from it the spermatozoa 

 pass out when the eggs are liberated. Extirpation of the annulus before 

 laying was followed by the death of the eggs, though they were laid and 

 attached to the female swimmerets as usual. It seems probable that 

 mechanical pressure exerted by the female brings about the discharge of 

 sperms from the receptacle at the time of laying. 



* Ceylon Pearl Oyster Report, Royal Society. Part ii. (1904) pp. 1S1-4 (1 pi.). 

 t Proc. Amer. Phil. Boa, xliv. (1905) pp. 91-136 (1 pi.). 

 \ Johns Hopkins Univ. Circular, 1905, No. 5, pp. 1-9 (1 pi.). 



