078 Transactions of the Society. 



called it var, constricta. It is somewhat larger and more robust 

 than the Caspian form, but otherwise differs but little ; striae 12-14 

 in "01 mm. 



GrOMPHONEME-E. 



Gomplionema (olivaeeum var.?) stauroneiformis Grun. — Q. 

 valvis lauceolatis vel subclavatis, obtusis, striis subradiantibus, sub- 

 tilissime punctatis, area transversa central! interruptis. Longit. 

 •053--07 mm.; latit. valv. •01--012 mm.; strire 10-13 in 

 •01 mm. Stipites plerumque longissimae. 



This Gomj)honema is distinguished from G. olivaeeum prin- 

 cipally by its greater size and more conspicuous, smooth, central 

 area. I have hitherto met with this form in mountain streams in 

 the Tyrol and Switzerland and presume that it has often been 

 mistaken for G. dichotomum. 



The forms from the Caspian Sea are still larger ("OOS-* 15 mm. 

 long) and might be called var. Caspia. The upper part is fre- 

 quently shorter than the lower; this is often the case with the 

 mountain species. 



Mastogloiace^. 



Mastogloia Smithii Thwaites var. intermedia Grun. — Minor, 

 valvis late, lanceolatis parum productis, nodulo centrali vix laterali- 

 ter dilatato, striis tenuioribus, 18-19 in '01 mm. Longit. '032- 

 •087 mm.; latit. •0125 mm. 



Harbour of Baku, common. 



Yar. ahnormis Grun. valvis lanceolatis, obtusiusculis, loculis ab 

 marginis remotis, lineae mediae approximatis, striis subradiantibus, 

 tenuissime punctatis, 18 in '01 mm. 



Baku Harbour, rare. 



A peculiar form, in which the loculi are apparently placed 

 between the margin and median line. I have observed something 

 similar in a Mastogloia from Seychelles, which I have named 

 M. Seyshellensis. It differs from the Caspian form by its greater 

 length and more lanceolate valves with occasionally capitate pro- 

 duced apices, and its delicate striae (26-29 in • 01 mm.). 



M. [Smitliii var. ?) fusilla Grun. — M. minuta, valvis lanceolatis 

 obtusiuscuHs, loculis mediis ceteros magnitudine superantibus, striis 

 subradiantibus, tenuissime punctatis, 17 in '01 mm., nodulo cen- 

 trah rotundato. Longit. • 012- -013 mm. ; latit. '007- "0075 mm. 

 Not common in the Harbour of Krasnowodsk. Eesembles M. 

 exigua of Lewis, but the valves are more obtuse and more strongly 

 striate ; the loculi are numerous and marginal. 



[I fail to detect any resemblance between the figure of If. exigua 

 and ill. imsiila ; the former has acute apices, loculi 2-5 (generally 

 only 3), striae obscure. In the latter the ends are obtuse, the 

 strice distinct, and the loculi numerous — F. K.J 



