DECAPODA 



391 



tcidhis, and AncistroteutJiis, the sessile arms have acetalnila only, 

 in Gonatus and Ahralia they have hooks as well, while in 

 Verania, Ancistrochin's and Unoj^loteutJiis, tlie sessile arms have 

 hooks only. The numher of rows of hooks or acetabula varies 

 with tlie different genera. 



¥am. 7. CJiiroteiithidae. — Head nearly as large as the body ; 

 fins terminal, tentacular arms very long, 

 sessile arms slightly wel)l)ed, acetabula 

 denticulated ; mantle-supports consisting 

 of cartilaginous ridges on the mantle, 

 wliich fit into corresponding depressions 

 on the funnel, gladius expanded at each 

 end. — Atlantic Ocean. 



The six dorsal arms in Histioteuthis 

 are miited by a broad wel), wdiile in 

 Histurpsis the web only reaches half 

 way up the arm. In Chiroteuthis the 

 tentacular arms have scattered sessile 

 suckers throughout their whole length, 

 and four rows of very long peduncu- 

 late suckers on the clubs. 



FA]\r. 8. CrandiUdae. — Head small, 

 body rounded, barrel-shaped, fins termi- 

 nal, eyes often very large, sessile arms 

 short, tentacular arms long, thread-like. 

 — World-wide. 



Cranchia proper has the tentacular 

 clubs finned, with eight rows of suckers, 

 body sometimes covered with warty 

 tubercles. Zolir/02'sts has a very attenu- 

 ated body, with fins tenuinally united ; 



, , 1 -,1 1 Fig. 251. — Tannins hyperboreus 



some species are spotted with colour, stp., N. Atlantic :.,., eyes ; 



or have rows of tubercles on the ventral /, /, fins ; f, t, tentacular 

 side. Taonius (Fig. 251) is doubtfully 

 distinct from Loligopsis. 



fins 

 (After Hoyle, x \). 



Order Tetrabranchiata 



Cephalopoda with four branchiae and four kidneys; animal 

 inhabitino- the last cliiiiiilici' of ;iu external multiloculai- shell; 



