179 



pear on the other lateral half; the proximal margin of the operculum 

 somewhat concave; the avicularian mandible triangular with linear 

 terminal part t. mamillaris Lamx. 



6) Two opesiulse of about the same size, both reaching the basal 

 wall; no spine-like processes; the zocecial aperture with a large discoi- 

 dal expansion distally, and the operculum, furnished with a correspon- 

 ding expansion, has a proximal straight margin; the avicularian man- 

 dible semielliptical with triangular opercular arch T. expansa n. sp. 



5) The proximal margin of the zocecial with a broad and deep sinus: 



7) Proximally to the opesiulse each lateral margin is prolonged into 

 a sharply projecting, thick-walled, semicircular or rounded triangular 

 process, inclining towards the cryptocyst; (the proximal margin of 

 the operculum with a continuous' chitinous sclerite; the avicularian 

 mandible triangular, only one opesiular outgrowth reaches the basal 



wall) T. cincta Hutton. 



7) No such processes: 



8) The opesiular outgrowths, of which in most (or all) zooecia only 

 one reaches the basal wall, meet the named wall in closed curved 

 lines; (the avicularian mandible broad, quadrangularly rounded, in the 

 proximal part narrowed; the smallest compasses with almost rectangular 

 opening) .■ T. novae hoUandiae Hasw. 



8) Both opesiular outgrowths reach the basal wall, on which they 

 form no closed curved lines: 



9) A short chitinous sclerite on either side of the proximal margin 

 of the operculum, the lateral margins of which are parallel; the avi- 

 cularian mandible narrow, claw-shaped, bent to one side ... T. falcifera Hincks. 



9) The proximal margin of the operculum with a continuous chiti- 

 nous sclerite and with lateral margins convergent distally; the avicu- 

 larian mandible has the form of an isosceles triangle; (on the basal 

 surface the two opesiular outgrowths may form sometimes two separate 

 lines, of which one is hook-shaped, sometimes a single continuous, 

 often trapeze-shaped, transverse line ; ooecia with pores) T. Harmeri n. sp. 



Thalamoporella lioticha (Ortmann). 

 Micropora lioticha Ortmann Archiv f. Naturgesch. 56 Jahrg, 1, 1890, pag. 30, 



Taf. II, Fig. 11a— b. 

 (PL VI, figs. 7 a-7 p, PI. VI b, fig. 4 a). 

 The zooecia, the length of which is between 0,79 and 0,99"'™-, have only 

 slightly developed, indistinctly marked and sometimes quite reduced adoral areas, 



12* 



