234 



Phasmidae*, the pair of abdominal evertible glands of tlie imago of 

 the Arctians, Pyrrhoretia isabella and Leucarctia acraea^. They differ 

 however in not being capable of withdrawal into the body-cavity, as 

 in numerous alcoholic specimens examined they are all of the same 

 general length and size, and moreover the cuticle at and near the base 

 is rough and spinulated like that on the other parts of the body, and 

 besides they are concealed by the dense hairs. I have not perceived 

 any odor emanating from these larvae , which are otherwise suffici- 

 ently protected by their venomous setae ; these larvae being difficult 

 to handle on this account. Further observations may prove that the 

 secretion is odorous , either oozing trough the rather thick cuticular 

 walls of the process, or remaining within the body and filling the 

 lumen. At all events, the unusual number (seven pairs) of such pro- 

 cesses ^ are an archaic feature, and in connection with the composite 

 or generalized structure of the insect in all its stages make it a remar- 

 kable and highly interesting form. 



Brown University, Providence, R. J. U. S. A. 



2. The Development of the Genital Organs, Pseudo-Heart (Ovoid Gland), 

 Axial and Aboral Sinuses in Amphiura Squamata. 



By E. W. Mac Br id e BA (Cantab.) BSc (London). 

 (Preliminary Notice.) 



eingeg. 21. April 1892. 



The investigations which form the subject of the present memoir 

 were carried on in the Zoological Station at Naples , during a period 

 of six months from October 1891 to April 1892. My original object 

 was to study the development of the genital] organs [in Echinoderms ; 

 and AmpJiiura squamata was the only form available at the time of my 

 arrival in Naples. 



In tracing the origin of the primitive germ cells , I soon disco- 

 vered their close relation to the organ which in England is generally 

 called the «heart« or »pseudoheart«. I then traced the development of 

 the latter and of the sinuses in connection with it: and so far as I can 



* S. H. S cu dd er, Odoriferous glands in Phasmidae. Psyche, I., 168, April 14 . 

 1876. 



5 J. B. Smith, Scent-organs in some Bombycid moths. Entomologica Ame- 

 ricana. II. No. 1. p. 79 — 80. July, 1886. — See also Morrison, H. K., On an appen- 

 dage of the male Leucarctia acraea. Psyche, I., p. 21 — 22. 1874. 



6 Here might be mentioned the 8 pairs of retractile lateral abdominal pro- 

 cesses 0Î Phyllocnistis , mentioned by Chambers in Psyche, III., p. 67, July, 1880, 

 Febr. 12, 1881. p. 135—137, the nature of which need further investigation. 



