64 SUMMARY OF CLfRRENT RESEARCHES RELATING TO 



Movements of Amphioxus.* — Leslie B. Arey has studied the move- 

 meuts of Branchiostoma carihhaemn Sundevall, common at Bermuda. It 

 can swim backward for short distances, but its normal orientation in 

 continued swimming is with the anterior end in advance. When a 

 somersault brings it tail-end in advance, another reversal follows directly, 

 or else the animal changes its course and returns more or less in the 

 direction from which it came. It burrows in the sand tail foremost. 



During locomotion the head and tail are bent simultaneously 

 toward the same side ; the posterior of all the flexures, which is by 

 far the most prominent, occurs approximately at the level of the 

 atriopore ; the next prominent flexure is at about the region of the 

 first gonads, but is much less extensive than the former. When the 

 animal is swimming slowly no other flexures are evident, except a 

 suggestion of one rather close behind the anterior flexure last described. 

 The occurrence of the two largest flexures just anterior and posterior to 

 the gonad-pouches suggests that these pouches materially increase the 

 rigidity of the body throughout the region where they occur, and thus 

 actually determine the position of the major flexures. As might be ex- 

 pected, when a forw'ard spring occurs the first flexure is initiated at the 

 anterior end, and muscular activity extends posteriorly like a w'ave ; when 

 the animal leaps backward the reverse is true. When the swimming 

 response is nearing completion, the rate of the muscular movements 

 rapidly decreases, and ends in complete collapse. After cessation of 

 movement, the animal is carried for a short distance by its own 

 momentum and then sinks slowly to the bottom. 



INVERTEBRATA. 



Mollusca. 



South African Marine Molluscs.! — Paul Bartsch reports on a large 

 collection of Molluscs made by Lieut. -Colonel W. H. Turton at Port 

 Alfred, and on others in the United States National Museum from the 

 South African faunal area. Numerous new species are described. 

 Attention is drawn to the prevalence of red coloration in Turton's 

 collection, which seems to be explained by the fact that the red algffi 

 form the dominant element in the marine vegetation of the region. 



Arthropoda. 

 a. Insecta. 



New England SarcophagidsB.J — Ralph R. Parker describes the ex- 

 ternal structure of the males of the genera Ravinia and Bmttcheria g.n. 

 A detailed account is given of the parts of head, thorax, and abdomen ; 

 the " vestiture " of these parts, i.e. the covering, exclusive of bristles or 



* Journ. Exper. Zool., xix. (1915) pp. 37-44. 



t Smithsonian Inst. U.S. Nat. Museum, Bull. 91 (1915) pp. 1-305 (53 pis.). 



X Proc. Boston Soc, xxxv. (1914, received 1915) pp. 1-77 (8 pis.). 



i 



