594 BIOLOGY. 



The abdomen or tail usually supports five pairs of 

 stunted feet, to which the ova hang. 



The number of maxillae agrees tolerably well with that 

 of the thoracic feet. 



Fam. 4. Mytiloid, Locust- Crabs. 



All the feet of pretty equal length, and the forceps 

 stunted in size ; the branchial plates free upon the 

 abdominal feet Squilla. 



Fam. 5. Arcaceous, Macroura. 



Abdominal feet arrested, branchial comb upon the 

 femora of the thoracic feet and beneath the dorsal shield, 

 tail extended, as in the common Cray-fish. 



Fam. 6. Oyster -like Crustacea, Br achy lira. 



Characters similar, but tail bent under the body 

 Taschenkrebse. 



COHORT II. SNAIL-LIKE CRUSTACEA ASSELN. 



3511. Body mostly cylindrical, annulate, without a 

 true carapax or scute ; head free ; feet short and simple ; 

 branchiae vesici- or folii-form ; mostly placed under the 

 tail ; eyes non-pediculated, or even wanting. 



Order 3. Androqynoid Sauqasseln. 



e/v t/ 



3512. Body soft and slightly annulate, maxillae, feet 

 and branchiae arrested ; live by suction as parasites upon 

 other animals, mostly fishes. 



Fam. 1. Tritonia-like , Lern&acece. 



Body soft, without shield, eyes and branchiae ; feet 

 and maxillae stunted; ova carried in two tubes at the 

 hinder part of the body Kiemenwiirmer or Lernea. 



Fam. 2. Patella-like, Argulacece. 



Body distinguished into head, thorax, and abdomen, 

 with few natatory feet, maxillae moulded to form suctorial 

 organs, mostly eyes ; lay also strings of ova ; head elon- 

 gated in many in a scutiform manner. The so-called 

 Fish-lice or Argulaceae. 



Fam. 3. Luftschneckenartige Pycnogonidce. 



Body short, with four pairs of long feet ; eves, but no 

 branchiae and maxillae; abdomen puny irr size. The 

 Wltale-lice. 



