1887.] DR. SHUFEI.DT ON THE ANATOMY OF CERTAIN AUKS. 4> 



many tenanted by other insects in various stages of transformation. 

 Like other spiders, when one meets another there is a fight, which 

 often ends in the death of both. 



The spider itself is a very interesting creature. It is about five- 

 twelfths of an inch in length ; its legs are short, strong, and flattish. 

 The head carries eight simple eyes ; the maxillary palpi of the female 

 are leg-like and hooked. There are four stigmata. The colour is 

 nearly black. The abdomen is not large in proportion to the rest of 

 the body, and bears at its extremity four spinnerets, two large and 

 two small. 



I send with this paper specimens of the houses and also of the 

 spider. In all cases the houses do not look so well, neither are 

 they so perfect as when fresh cut from the trees ; this is partly 

 owing to the shrinking and twisting of the bark in drying. If I can 

 give any other information respecting this spider, or if it would be 

 acceptable to you for me to send other accounts of personal observa- 

 tion, I shall be pleased to do what I can, according to the limited 

 time I have for this, my favourite pleasure. 



4. Notes on the Visceral Anatomy of certain A.uks. 

 By R. W. Shufeldt, C.M.Z.S. &c. 



[Received November 12, 1886.] 



About two years ago the Smithsonian Institution of Washington 

 placed in my hands for anatomical description a fine collection of 

 bird-skeletons, amounting to nearly a hundred in number, that had 

 been collected by American explorers at different times and at several 

 localities in the Arctic regions. My researches upon this material 

 will quite fill a volume, and are illusLrated by several hundred 

 original drawings, the whole being in charge of the Smithsonian 

 Institution for pubhcation. When I received this collection it 

 was accompanied by a few selected alcoholic specimens of Alba- 

 trosses and Auks, sent to me with them in order that I might 

 obtain skeletons that were not to be found among the rest of the 

 material, my work having chiefly to do with the osteology of the 

 groups represented. Among the spirit-specimens of the Auks I 

 found one of each of the two interesting forms known to us as 

 Brachyrhamphus marmoratus and Syntliliborhamphus antiquus, or 

 the Marbled Murrelet and Ancient Murrelet respectively. These 

 birds rarely fall into the hands of anatomists in such good condition 

 as these were ; and although I only needed their skeletons for the 

 purpose I had in view at the time, I nevertheless took the pains to 

 carefully remove certain parts of their visceral anatomy, and again 

 placing these parts back in the alcohol, I have them now before me 

 for examination. 



My surprise was very great to find in these two forms, supposed to 

 he very closely related generically, how very different the correspond- 

 ing structures and organs occupying the chest and abdomen really 

 were. Some of these differences will be readily appreciated by simply 



