Miscellaneous. 151 



special maimer in my researches, b^t equally, to ajl the Araneidce, as 

 I have since convinced myself. r .if jKroijifR ,t, i,. ,; / , 



In these Articulata, the heart, usually divided into five chambers, 

 offers four pairs of auriculo- ventricular orifices; the aorta, which 

 springs from the anterior chamber, penetrates into the thorax and 

 furnishes two arteries on each side, the branches of which are distri- 

 buted to the posterior diverticula of the stomach and to the thoracic 

 muscles. Beyond this the aorta divides into two great trunks, which 

 above give off the arteries of the first diverticula of the stomach and 

 of all the muscles of the anterior portion of the thorax. The oph- 

 thalmic arteries spring from the inner part of each of these trunks. 

 Below, they are prolonged to form the arteries of the mandibles 

 {antennes pinces), and about their median portion they furnish a 

 voluminous artery which divides immediately to form the arteries of 

 the legs and of the ventral portion of the abdomen. All these vessels 

 present a number of branches and ramifications not inferior to those 

 which are generally seen in vertebrated animals. Besides these, each 

 of the chambers of the heart furnishes a large artery on each side, 

 the branches of which are distributed to the liver and intestines. 



For the return of the blood the circulatory apparatus is much less 

 perfect ; in general there only exist canals, the walls of which are in- 

 capable of being isolated by dissection. Nevertheless, the legs and 

 the mandibles {antennes pinces) are penetrated by a very distinctly 

 limited venous canal ; but in the thorax the principal passages are 

 merely circumscribed by the bundles of muscles. On the other hand, 

 in the liver, we observe, at various points and principally on the sides, 

 vestiges of membranous walls. 



All the venous blood collected from the different parts of the body 

 is conducted into the lower region of the abdomen, where it is intro- 

 duced into the respiratory organs, by means of two large pulmonary 

 canals formed by a delicate membrane ; arrived at the organs of re- 

 spiration, the nutritive fluid soon passes into the pulmono-cardiac ves- 

 sels, which are equal in number to the auriculo-ventricular orifices of 

 the heart, into which they empty themselves. These vessels, of a 

 very delicate consistency, are always adherent to the inner walls of 

 the abdominal teguments. 



Thus the circulation of the blood in the Arachnida is executed by 

 means of an arterial system of the most complete description ; and 

 a venous system, which, although no doubt very imperfect when 

 compared with that of the Vertebrata, offers, nevertheless, in the re- 

 gularity of its course and the well-circumscribed limits of most of its 

 passages, a degree of complication of which naturalists hitherto could 

 have formed no idea. — Comptes llendusy March 15, 1852, p. 402. 



ON THE DISTRIBUTION OF COLUBER NATRIX. 



Referring to Mr. Gray's article in the June Number of the * An- 

 nals of Natural History,' on the distribution of the Coluber natrix, I 

 beg to state that it is a mistake to suppose that this reptile is not 

 found in Norfolk. I have seen specimens from two localities in East 

 Norfolk, and I have heard of them in West Norfolk. I have also 



