THE SQUIDS. 5\)3 



Squids, are distinguished by their elongated bodies, their short and 

 broad fins, and the horny shell or pen which is found in their in- 

 terior. All the Squids are very active, and some species, called Fly- 

 ing Squids by sailors and Ommastrephes by systematic naturalists, are 

 able to dash out of the sea and dart to considerable distances. 



The Little Squid, or Sepiola, of which genus six species are known, 

 inhabits most parts of the world and lives on our own shores. 



The celebrated " ink " of these creatures, from which the valuable 

 color called " sepia " was formerly obtained, deserves a brief notice. 



This substance is liquid, and is secreted in a sac popularly termed, 

 from its office, the " ink-bag." The sac is filled with a spongy kind of 

 matter, in which the ink lies, and from which it can be expelled forci- 

 bly at the will of the animal. The ink-bag is not always in the same 

 position, but some species ha.ve it in the liver, others near the siphon, 

 and others among the viscera. There is a communication between the 

 ink-bag and the siphon, so that when the ink is ejected it is forcibly 

 thrown out together with the water. Thus the very effort for escape 

 serves the double purpose of urging the creature away from danger and 

 discoloring the water in which it swims. 



The animal can eject the ink with such force that it has been known 

 to dedecorate a naval officer's white duck trousers with its liquid mis- 

 sile, the aggrieved individual always asserting that it took a deliberate 

 aim for that purpose. 



Generally, the animal throws out its ink on the least alarm — a cir- 

 cumstance of some importance in geology. It was discovered by Dr. 

 Buckland that in many specimens of fossil cephalopods, called scien- 

 tifically Geoteuthis — i. e., Earth Squid — the ink-bag remained in the 

 animal untouched by its long sojourn within the earth, and even re- 

 tained its quality of rapid mixture with water. A drawing was act- 

 ually made by Sir F. Chantrey with a portion of "sepia" taken from 

 a fossil species, and the substance proved to be of such excellent quality 

 that an artist to whom the sketch was shown was desirous of learning 

 the name of the color-man who prepared the tint. 



The curious skeleton of the Sepia, popularly called " cuttle-bone," 

 is composed of many tiers of tiny chalk pillars, which can be seen only 

 by the aid of the microscope. 



Another order of cephalopods is called by the name of Tetrabranchi- 

 ata, or Four-gilled Animals, because the organs of respiration are com- 

 posed of four branchiae. These creatures possess a very strong exter- 

 nal shell, which is divided into a series of gradually-increasing com- 

 partments connected together by a central tube called the siphuncle. 

 As the animal grows it continues to enlarge its home, so that its age 

 can be inferred from the number of chambers comprising its shell. 



In former days these creatures w^ere very abundant, but in our day 

 60 * 2 N 



