proceedings: biological society 579 



is a modified dip net, the hoop of which is set at right angles to the pole. 



The spawning season is in the spring from the latter part of Febru- 

 ary to the first half of May. The act of spawning was observed at the 

 biological station. The female remains in an upright position, and the 

 seminal vesicle is scraped off by using the fifth pair of dactyls just 

 before the eggs are extruded. The eggs are all laid in about six hours. 

 They are carried on the last three pairs of pleopods, but it is not known 

 how they are attached. The incubation period was observed to be 

 eighteen days. The eggs change in color from red to gray as the yolk 

 material is absorbed. The eggs were hatched at Key West in McDon- 

 ald jars and the first larv^a or phyllosome was recovered. 



The female molts from seven to ten days after the eggs hatch and 

 mating occurs while the shell is still soft. The copulation act follows 

 Astacus in details more closely than Homarus or Cambarus, the female 

 lying on her back with the male standing over her. 



The molting act was observed, the shell splitting along the sides of 

 the carapace and rising upward and forward as the cephalothorax is 

 withdrawn. The shell hardens in from eighteen days to three weeks 

 to the extent that it cannot be indented by the fingers. {Author's ab- 

 stract.) 



The paper was illustrated by lantern slide views of lobster houses, 

 eggs, larvae, and adult lobsters. Mr. Waldo Schmidt discussed the 

 paper, showing by means of a map the distribution of the larvae of 

 the spiny lobster off the southern California coast. 



609TH MEETING 



The 609th meeting was held March 20, 1920, in the lecture hall of 

 the Cosmos Club. Dr. A. D. Hopkins called the meeting to order at 

 8 p.m., with 47 persons present. The minutes of the 6o8th meeting 

 were read and approved. Upon the recommendation of the Council, 

 Miss K. G. Symmonds of Washington was elected to active membership. 



Under the heading of Brief notes and exhibition of specimens, Dr. R. 

 W. vShuf^ldT exhibited a specimen of the Moloch {Molochius horridus), 

 a lizard from Australia. It is fairly common and feeds upon ants, 

 especially upon a certain malodorous form which infests houses. These 

 lizards are sometimes encouraged to live in houses to keep the houses 

 free from the w^orse evil. Thousands of ants may be eaten bv the 

 lizard at a meal. 



Dr. L. O. Howard commented upon the severe cutting back of the 

 sycamore trees on a portion of Eleventh vStreet, said to be done on ac- 

 count of a blight. Dr. M. B. Waite further remarked that the blight 

 of sycamore was common in the District, causing long shoots. It is 

 not known that the cutting of the trees back in such drastic manner 

 will control the blight, yet the trees will endure the treatment and 

 develop symmetrical leafy tops. 



Mr. Thomas E. Snyder exhibited a photograph of a nest of an ant. 

 The nest is similar in external appearance to the nests of some termites 

 which build above ground. 



