110 



Transactions. — Zoology. 



Order. 



Characteristics. 



Family. 



Characteristics. 



Sub-order 

 Loricata 

 — contd. 



Scirtopoda 



Coluridse 



Pterodinadse 



BrachionidEs 



Anuraeadse 



PedalionidEe 



Body enclosed in a lorica 

 usually of firm consistence, 

 variously compressed or de- 

 pressed, open at both ends, 

 closed dorsally, usually open 

 ventrally. Head with chi- 

 tinous hood. Toes two, 

 rarely one, always exposed. 



Lorica entire, various ; corona 

 and wreath those of Philo- 

 dinidcB. Trophi malleo-ra- 

 mate. Foot wholly retrac- 

 tile, transversely wrinkled, 

 jointless, toeless, ending in a 

 ciliated cup, or foot absent. 



Lorica box-like, open at 

 each end, generally armed 

 with anterior and posterior 

 spines. Foot long, exces- 

 sively flexible, wholly re- 

 tractile, wrinkled, and two- 

 toed. 



Lorica box-like, broadly open 

 in front, behind open by only 

 a narrow slit ; usually armed 

 with setae. Foot wholly 

 wanting. 



Arthropodous limbs six ; co- 

 rona of two concave lobes ; 

 ciliary wreaths as in Philo- 

 dinidcB. Trophi malleo-ra- 

 mate. 



The different types of trophi are referred to under the 

 names given to them by Hudson. He presumes the typical 

 form of mastax to be that found in Brachionus iirceolaris 

 (Journal Mic. Sci., xxiv., 350). There are two hammer-like 

 bodies (mallei) {c,d), which work on a split anvil (incus) (e, /). 

 Each malleus consists of an upper part, or head (uncus) {d), and 

 a lower part, or handle (manubrium) (c). The incus also con- 

 sists of two parts, the upper divided into two symmetrical 

 halves (rami) (e), which are supported on a lower piece 

 (fulcrum) (/). There the mallei are prominent, but all the 

 other types of trophi are marked by successive degradations 

 of the mallei and increase of the incus. The following are the 

 seven chief types of trophi : — 



1. Malleate. — Mallei stout ; manubria and unci of equal 

 lengh ; unci 5- to 7-toothed ; fulcrum short. (Brachionus.) 



2. Suh-malleate. — Mallei slender ; manubria about twice 

 as long as unci ; unci 3- to 5-toothed. {Euchlanis.) 



