IN THE MUD OF THE LEVANT. 



17 



coasts, but differs from the present form in having 

 its lateral surfaces less concave. It may, however, 

 only be a variety ; as many of the Diatomaceae 

 exhibit considerable variations of form in the same 

 species. 



Grammatophora presents at least two species, 

 O.A/ricana, Ehr. (figs. 4. 6.— fig. 8. is probably a 

 small variety of the same—*), and G. tseniseformis 

 (fig. 7, and probably fig. 9.) The former of 

 these species occurs on our coasts. I have 

 received it from Mr. Ralfs, who collected it at 

 Ilfracombe ; and I have met with it rather abund- 

 antly, along with G. taniseformis, in the stomachs 

 of crabs from the west coast of Scotland. It 

 is one of the most beautiful of this interesting 

 group, and when occurring in long, zigzag chains, 

 the partially separated frustules cohering by the 

 angles, it constitutes an exquisite microscopic 



* Mr. Ralfs writes to me, " Kutzing names my Striatella 

 taenigeformis, var y serpentina, Grammatophora serpentina, 

 with the following synonyms :— Stri. tseniseformis y serpen- 

 tina, Ralfs. Grammatophora Africana, Ehr.? so that, pro- 

 bably, it is Ehrenberg's species." Under Grammatophora 

 marina, Kutzing has the following synonyms :— Conf. tsenise- 

 formis E. B. Diat. marinum Lyngb. Diat. tseniseformse, 

 marinum and Lyngbyei, Ag.— Bacillaria Cleopatra and Gram- 

 matophora Oceanica, Ehr. 

 D 



