330 Annah of the South African Mnse'inn. 



about eight in number on each side, each of the spines only accom- 

 panied by a single spinule ; apical claws each with an extremely 

 minute denticle at the base. 



Colour reddish-orange. 



Length of shell scarcely exceeding O9 mm. 



Remarks. This form was described by the present author in both 

 sexes as early as the year 1895 from specimens raised out of mud 

 taken at Kuysna. It was, however, at that time erroneously identified 

 with the European species L. acanthocercoides (Fischer), from which 

 it in reality differs, both in the general outline of the shell and in the 

 larger size of the eye as compared with the ocellus. The form 

 recorded by Mr. G-urney from Kroonstad as L. africana is scarcely 

 different from the present species. 



Occurrence. Besides from the Knysua-mud, I have reared this 

 form rather abundantly from some of the parcels of mud kindly 

 forwarded to me in 1909 by Dr. Purcell, and taken in the neighbour- 

 hood of Bergvliet. 



Distribution. Sumatra. 



28. LEYDIGIA MICROPS, n. sp. 

 (Plate XXXVIII, figs. 2, 2 -:/.) 



Specific Characters Female. Shell, seen laterally, of the usual 

 broadly triangular form, with the dorsal margin somewhat irregularly 

 curved ; hind edges of valves obliquely arcuate, without any obvious 

 bulging in the middle. Head comparatively more produced than in 

 the two preceding species, with the rostral projection acuminate and 

 slightly recurved at the end. Surface of valves sculptured with rather 

 faint longitudinal striae. Eye extremely small, puiictiform ; ocellus 

 well developed, resembling in size and shape that in L. projiinqt/.a ; 

 its distance from the eye scarcely more than half that from the tip of 

 the rostrum. Antennulae not nearly extending as far as the latter. 

 Tail-piece less expanded than in the two preceding species and 

 obtusely truncated at the end, hind edge nearly straight and joining 

 the end edge by a strong curve ; sub-marginal spines rather numerous, 

 twelve to fourteen on each side, but rapidly diminishing in size proxi- 

 mally, each spine being accompanied by a somewhat smaller spiuule ; 

 apical claws each with a series of very delicate denticles in their 

 proximal half. 



Male much smaller than female and having the dorsal margin of 

 the carapace straight. Antennulae much thicker than in female. 

 First pair of legs each armed with a very strong hook. Tail-piece very 



