228 CEYLON PEARL OYSTER REPORT. 



ampullcB. These masses of Ramulina herdmani may be in places predominantly 

 ampullate in their mode of growth, as in text-fig. C, which shows an irregular mass 

 of ampulla? opening into one another at different angles, and not lying simply in one 

 and the same plane. In fig. A, on the other hand, the ampulla? are arranged in 

 definite planes (not parallel to one another), and between these planes pass the pipes 

 opening into the ampulla? at either end. The larger piece, shown in fig. B, is almost 

 wholly composed of pipes, with only a suggestion of ampulla?, or perhaps two or 

 three where several pipes open near each other. 



The walls of the pipes and ampulla? are strong, calcareous, but not hyaline, and in 

 some places as much as 0"065 millim. in thickness ; but about - 05 millim. is the 

 average. All these walls are uniformly perforate, but the external surface differs in 

 appearance in places, being sometimes quite smooth and elsewhere bearing minute 

 denticles, either sparsely or more closely set. There also seem to be definite larger 

 openings to the exterior, or mouths (see Plate, fig. 5). These are quite large 

 openings, about 2 - 5 millims. across, and are situated where one or two ampulla? 

 meet. They do not occur very frequently. 



At such mouths the walls of the ampulla? are prolonged to form 4 to 6 protuber- 

 ances of unequal size which surround the orifice. 



In accordance with this description of the new species, the definition of the genus 

 requires to be somewhat modified which, however, was necessary before, since the 

 original definition will not include Wright's Rarmdina aculeata. 



The definition of the genus given by Brady was quoted above. I should suggest 

 that this be now modified so as to read : Test free, or adherent, branching and 

 anastomosing ; consisting of a calcareous tube, swollen at intervals to form more or 

 less definite, often irregular segments (ampullm), opening into one another and being 

 contiguous, or separated and, connected by tubules. From these segments straight 

 tubes (pipes) five given off. Texture hyaline or opaque. 



The alterations or additions are printed in italics. The definition of the new 

 species will be given at its systematic position in the catalogue that follows. 



LIST OF SPECIES. 



Family: MILIOLIILK. 

 Biloculina riugens (Lamarck). 

 This form occurs rarely in the deposit from Stat.* LXVIII. It has been recorded 

 (2),t (4) from the Indian seas. 



Biloculina ringens, var. striolata, Brady. 

 Of very rare occurrence in material from Stat. LXIV., south of Modragam Paar, 

 depth 5 fathoms. This variety has also been recorded from the Indian seas (2). 



* For particulars as to the Stations see "Narrative," this Report, Part I., 1903, p. 17. 

 t These numbers refer to the bibliography at the end. 



