640 



SCIENCE 



|Voi.. II.. No. Jl. 



«ir. Water- vapor is not nearly so diathermoiis 

 as Avy air. Much of the heat that would pass 

 down to the sand on the desert is held back 

 \)y the vapor over the ocean, and some is 

 caught again from the lieat radiated upwards 

 by the water, so that a considerable thickness 

 •of air is warmed. Of still more importance is 

 the vapor's action as a great storehouse of 

 solar force, required in the process of its evap- 

 oration, generally known as ' latent heat.' For 

 &\\ these reasons, the accumulation of energy 

 in the preparation for an oceanic cyclone is 

 vastly greater than in the making ready for a 

 ■desert-whirl. 



( To be continued.) 



REMARKS UPON THE OSTEOLOGY OF 

 PHALACROCORAX BICRISTATUS 



It is a fortunate thing for science, that time 

 allowed manj' of our Alaskan explorers to 

 bring back in their collections, and to the mu- 

 seums, skeletons of so many of the rarer forms 

 of the vertebrates, particularly the birds of 

 those unfrequented regions. To Dr. T. II. 

 Bean and Mr. H. W. Elliott, both of the 

 Smithsonian institution, we are under lasting 

 obligations for such material, and for making 

 so good use of their advantages. The writer 

 lias enjoyed the unusual privilege of examin- 

 ing and studying long series of skeletons of 

 Lobipes hypcrboreus, Haematopus niger, rare 

 forms of Eissa, Larus, and Sterna, many of 



in the second volume of his ' Comparative 

 anatomy and physiology of vertebrates,' on 

 p. 64, speaks of a bony style that is attached 

 to the occiput in the cormorant as one of tlie 

 cranial peculiarities of the class. This author 

 does not mention its use ; and as the writer 

 has not a cormorant before him intact, with 

 all the soft parts, it would be hardly safe to 

 give its exact function in this bird's econ- 

 omy : but as I do not believe we have a figure 

 showing the site of this bonelct, an illustration 

 of the skull of Phalacrocorax is here given, 

 showing, life-size, the right lateral view. 

 This prominent style is seen protruding from 

 the summit of the occiput in my drawing, not 

 as a spinous outgrowth fi'om that point, but 

 rather as a free bone, concave below, separated 

 into two concavities on its superior aspect lij' 

 a sharp median crest that is developed on its 

 entire length, — a transverse elliptical facet an- 

 teriorly, that articulates freely witli a corre- 

 sponding one on the occiput. 



At the base of tlic cranium, we find that the 

 pterygoids are completely overshadowed bj- 

 the sub-compressed but rather large brain-ease 

 above. There are no basi-sphenoidal processes 

 thrown out to meet these bones. The. poste- 

 rior halves of the palatines form a close union 

 all along their median and inner margins, 

 which portions are much spread out horizon- 

 tallj'. Beyond, they become narrower ; and in 

 the space that we find existing between them 

 we observe a long attenuated vomer, terminat- 

 ing anteriorly in a free, pointed extremitj-. 

 The coimorants belong to the Dysporomor- 

 phae of Professor Iluxlej's classification ; and 

 he and other eminent anatomists have given 

 othei c '•nial characteristics in their' descrip- 



pital style, St. o. 



the auks, putlius, and the like, — nearly all 

 from the source that I have mentioned. 



It was during the course of vay examination 

 of these sub-arctic rarities that mj- attention 

 was called to several points of interest in a set 

 of skeletons, representing three young and an 

 old one, of a species of cormorant, Phalacro- 

 corax bicristatus, forming part of the collection 

 of the last-named naturalist. Professor Owen, 



tions of this well-defined group. Tiie rami 

 of the lower mandible are deeply grooved on 

 the inner aspects of the deutary portion ; and * 

 these elenrents, originally free,, retain their 

 sutures, distinctly marked, through life, where 

 thej' join the other interested segments at the 

 posterior moiety. Seventeen vertebrae are 

 found in the cervical region, before we arrive 

 at one that bears a free pair of ribs. Of this 



