17G SUMMARY OF CURRENT RESEARCHES RELATING TO 



Four species are recorded from this neighbourhood for the first time. 

 The depths at which the specimens were taken range from three to 

 fourteen fathoms, in all cases comparatively shallow water. They 

 usually live in clean coarse sand and feed largely on diatoms. The 

 spawning time in tropical seas appears to be the latter half of March, 

 rather earlier in the year than in more temperate seas. It is noted that 

 Branchiostomum lanceolatum, now for the first time recorded from the 

 Indian Ocean, is cosmopolitan, that the variety B. belcheri is the pre- 

 dominant form, that B. pelagic urn is truly pelagic, and that B. cali- 

 fornieiise occurs, though showing some slight variation when compared 

 with its American relations. Tattersall's tables show how extremely 

 variable the species of this group are ; " the more extended our know- 

 ledge of this group becomes, the less distinctly do the species appear to 

 be separated." 



IN VERTEBR AT A . 



Enemies of the Sugar Beet.* — A. Stift has notes on the injurious 

 effects of Eurycreou sticticalis (caterpillars), Bibio hortulans, Anthomgia 

 co/iformis, Aphis papaveris, lulus guttulatus, Heterodera schachtii, and 

 other forms which prey upon the beet. He also refers to the injuries 

 done to winter wheat by Geophilus longicomis. 



Mollusca. 

 y. Gastropoda. 



Blood of Marine Gastropods. f — E. Couvreur has studied the blood 

 of Murex braiularis, M. trunculus, and Tritonium nodiferum. There is 

 a general resemblance with the blood of the snail. The fresh blood is 

 almost colourless, but acquires a faint blue tint due to hasmocyanin ; 

 there is no spontaneous coagulation, there being no fibrin-forming sub- 

 stance ; a little sugar is present. 



5. Lamellibranchiata. 



Variations in Pecten opercularis.J — C. B. Davenport has com- 

 pared three lots of individuals from widely separated localities, — Eddy- 

 stone, Firth of Forth, and the Irish Sea. He discusses change of 

 proportions with age, changes in symmetry, ray frequency, variation of 

 the " ears," colour variations, and abnormalities. 



In some studies on Pecten irradians from the American coast, 

 Davenport was struck by the gradual change of the shells from place 

 to place ; a change of such a nature that one might say that the dif- 

 ference in the place modes was a function of the spatial interval between 

 the places in question. 



Davenport's study of Pecten opercularis from British coasts yields 

 a similar result. The three lots collected from three places are measur- 

 ably unlike in size, proportions, and average number of rays. When 



* Zeitsclir. Zucker Industrie und Landwirtsekaft, 1903, p. 3. See Centralbl. 

 Bakt. Parasitenk, 2 ,e Abt., x. (1903) pp. 611-5. 



t Ann. Soc. Linn. Lyon, lxxxix. (1903) pp. 79-81. 



t Proc. Anier. Acad., xxxix. (1889) pp. 123-59, many tables. 



