776 SCIENTIFIC RECORD FOR 1885. 



just beneath the water, and, with a few violent throes, expelled a black 

 mass, which fell slowly through the water, and before it reached the 

 bottom resolved itself into one of the worms. " The cricket seemed ex- 

 hausted by the horrid birth, and did not find strength to draw itself up 

 on the edge of the pail for about eight minutes, and when it finally did 

 so, it tumbled to the floor and crawled off in a very rheumatic manner. 

 After this discovery we used to amuse leisure hours by watching like 

 operations until frost killed the crickets. I sometimes would crush 

 large crickets, generally with the result that a tightly-coiled snake 

 would be thrust out of a rupture just above the tip of the abdomen ; 

 but whether the snake was not sufficiently develoiied or because of its 

 needing water rather than air to vitalize it, none of the snakes so pro- 

 duced showed any signs of life." 



MOLLUSCOIDS. 



Polyzoans. 



Use of aricularm in classification of the Polyzoans. — The so-called 

 chitinous j^arts (operculum and avicularia) of the Polyzoans had been 

 much neglected until lately, but Messrs. A. W. Waters and G. Busk 

 have paid special attention to such parts with decided benefit to the 

 systematic arrangement of the chilos-tomata. The modifications of the 

 operculum especially were described when practicable by Mr. Busk in 

 his elaborate report on the species collected by the Challenger exi)edi- 

 tion. The avicularian mandibles were also investigated to some extent 

 by Mr. Busk ; and, according to Mr. Waters, " to him we must give the 

 credit of first applying the form of the mandible in specific determina- 

 tion." A fuller discussion "On the use of the avicnlarian mandible in 

 the determation of the chilostomatous Bryoaoa or Polyzoa" has been 

 contributed by Mr. Arthur W. Waters. Yarious points are discussed, 

 but only a couple can be here noticed. "The process in the chitinous 

 mandibles" Mr. Busk calls a columella, and says that "it is covered with 

 short hairs," but these, upon comparison with other mandibles, turn out 

 only to be the remains of the attachment of the muscular threads. In 

 fine, the processes in the mandibles, especially of Cellepora and Adeona, 

 " indicate differences in the muscular attachments, and both here and 

 in the opercula it is really the muscular system which has the greatest 

 classificatory value ; but this is best studied by means of the variations 

 in the chitinous parts." (J. B. M. 8. (2), v. 5, pp. 774-779, pi. 14.) 



Brachiopods. 



Vascular and nervous systems of Brachiopods. — Some points in the 

 structure of the Brachiopods are very difficult to determine for one rea- 

 son or another, but new light is gradually being thrown on such. Sev- 

 eral doubtful points have been investigated by Dr. F. Blochmann. The 

 heart and its contractibility were early correctly observed by Professor 



