Notes on the Famil// Cotlinpnidoe. Bij J. Murray, 559 



The animal was only studied while alive, so I failed to secure 

 many details which can only be seen in the contracted state, such 

 as the form of the ventral plate and of the frontal border. I have 

 noted that the lorica is perfectly hyaline and flexible. The eye is 

 clear and colourless. As it swims the animal rotates on its long 

 axis in the manner of a Mastir/ocerca. 



It has been suggested that the curvature of the toe is a de- 

 formity, and in view of the possibility I refrained from describing 

 the species earlier. Having now a much wider acquaintance with 

 the family, I see that if we imagine the toe straightened out it 

 would still be quite unlike any known Monostyla, and so I venture 

 to describe it, despite the incompleteness of the study. 



Halitat. — In a small stream on the island of St. Kilda, 1904 ; 

 a single example. 



Ehrenberg {15) figures a variety of M. htnaris having a falcate 

 toe, which may have been this species. 



Monostyla sp. (?) Plate XXIII, 20a-20&. 



Description. — Smallish, pyriform, moderately excavate in front, 

 more deeply on ventral side ; posterior lobe prominent, rounded ; 

 dorsal plate broader. Toe of moderate length, shouldered and 

 clawed. 



Length of contracted lorica 90 yLt, of dorsal plate 80 fx, of toe 

 50 /A ; breadth of dorsal plate 75 fju, of ventral plate 65 jm, of 

 anterior border 50 ^. 



The dorsal anterior excavation is in three straight parts, the 

 ventral in two straight lines with a U in the middle. The dorsal 

 plate is obscurely rhomboid, considerably narrowed at both ends. 

 Ventral plate constricted near the front. Toe rather broad, margin 

 undulate, shoulders rounded, claw short. 



The lorica is very like that of a species discovered by Harring, 

 and not yet described, but it has a much longer and more slender 

 toe. 



Specimen in Mr. Eousselet's collection. 



PKOVISIONAL LISTS OF ADMITTED AND 

 REJECTED SPECIES. 



Although it may be impossible at the present moment to 

 pronounce authoritatively upon the values of all the reputed 

 species of Cathypnidse, it may be of some help to other students of the 

 family if I give my estimate of values after examining the great 

 majority of the species. There are many hopelessly inadequate de- 

 scriptions, and there are many synonyms about which there can be no 

 manner of doubt. It should clear the ground if these are indicated. 



