KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 22. N:0 8. 45 



Long. sin. acul. 34 ,«; lat. 28 ft; crass. 18 ,". 



Teremakau et Arahura (22). 



One spine wlrich according to rule ought to be placed at the lower angle of the 

 seinieell, may, as appears from fig. 29 a, reach higher up the middle of its side. If the 

 spines had been shörter, and the projection on the middle of the semieell almost imper- 

 eeptible, it would have been more correct to associate it with X. oct&cprne, which pvoves 

 how near to each other these 2 species do come. 



8. X. inehoatum nov. sp. Tab. 4, fig. 30. 



X. fere tam latum quam longuin, constrictione mediana lineari angusta, seinieellula 1 

 suboblongo-hexagome (fere ut in X. antilopceo) angulis superioribus aculeos singulos geren- 

 tibus; a vertice visas elliptiete utroque polo inträ marginen) aculeo; a latere late obovatae 

 apiee aculeo praeditae. Membrana in centro seinicellularum incrassata. 



A X. aniilopcuo prsBcipue differt aculeis non geminatis sed tantum 2 in utroque 

 semicellula. 



Long. 36 — 38 ,", lat. 40 — 44 ,u; lat. isthm. 10 — 12 ,u; crass. 23 ,«; long. acul. 6 — 10, «. 



Taupo- (154); Omatangi (244, 248, 253, 260). 



Una cellula e Taupo (157) paullulo minor est aculeis, bene evolutis, ])aullo longiori- 

 bus. Long. sin. acul. = lat. s. acul. 36 ,«, long. acul. 14 ,"•. Ad Arthrodesmum lncudem 

 Wolle Unit. St. Desm. tab. 24, fig. 1 (»large form») accedens. 



Gen. 13. Arthrodesmus Eiiwknb. 



1. A. coiivergens Ehkenb. Infus. p. 152, tab. 10, lig. 18; Ralfs Brit, Desm. tab. 20, fig. 3 b. 



Long. 52 ,«; lat, 46 ,«; crass. circ. 24 ,u. 

 Taupo (155). 



2. A. Incus (Bi^éb.) Hass. Brit, Fr. Alg. p. 357; Cosmarium Incus Bréb. in Menegh. 



Syn. Desm. p. 228. 

 Forma cum fig. 4 a, c et d in Ralfs Brit, Desm. tab. 20 fere prorsus congruens. 

 Long. sin. acul. 24 ,«; lat sin. acul. 24—26 ,u; crass. 13 ,«; long. acul. 10 — 12 ,«. 

 Omatangi (240). 



— i# intermedius Wittk. Anteckn. Sv. Desm. p. 15, tab. 1, fig. 6. 

 Forma isthmo paullum angustiore. (Cfr. Staur. pterosporum). Long. sin. acul. = 

 lat. s. acul. 10 ,"; lat. c. acul. 15 fi. 

 Omatangi (240). 



Gen. 14. Cosmarium Couda; Ralfs. 

 1. C. sublatum nov. spec. ad inter. Tab. 5, fig. 1 — 4. 



C. magnum subquadratum profunde constrictukn sinu mecliano lineari angusto intimo 

 et extremo dilatato; semicellulaj rectangulares, rariter sursum dilatatae (fig. 3) angulis 



