W. D. Lang — On Stomatojjora antiqua. 265 



III. Stomatopora Richardsoni, sp. NOV. (PI. XIV, Figs. 8 and 9.) 



A specimen has been found in the Lias of Toddington, north-east 

 ■of Cheltenham, Gloucestershire, by Mr. L, Eichardson, F.G.S., 

 which in its early stages resembles S. antiqua, Haime. Branching 

 after Type II occurs as early as the second or third dichotomy, and 

 is general by the fourth, at which point the zoarium has become 

 Proboscinoid. This early branching after Type II is represented 

 in Diagram I, p. 267, Fig. 5, where only the Stomatoporoid stages 

 are shown, and the branching not carried beyond dichotomy 3, in 

 order that an equal comparison may be made with the other forms 

 figured. The irregularity in the branching is retained throughout 

 the Stomatoporoid stages, showing this to be a primitive character 

 ■directly derived from S. antiqua, Haime, and not, as appears to be 

 ■the case in certain Oolitic forms, a secondary irregularity following 

 •normal branching after Type II, and giving rise to such forms as 

 Proboscina morinica (Sauvage). The tendency of the sides of the 

 zoarium to become flattened out on the object encrusted so as to 

 form a 'selvage,' as Gregory calls it,Ms more pronounced than in 

 S. antiqua, Haime, and produces in the distal part of the zoarium 

 the type of Proboscina resembling the species above mentioned. 



The slight pyriformation exhibited by S. antiqua, Haime, between 

 ■dichotomies 1 and 2 is absent. The zooecia are cylindrical throughout 

 after the first dichotomy. 



It will be seen on referring to Pi. XIV, Fig. 8, that after the 

 first dichotomy the right-hand branch is more specialized -and 

 becomes Proboscinoid sooner than the left-hand branch. A second 

 zoarium on the same specimen exhibits similar characters to that 

 described and figured, as far as can be seen through the obscuring 

 matrix. 



The zone in which this specimen was obtained was probably that 

 ■of Uptonia Jamesoni. At any rate this is the approximate horizon. 



Three more zoaria (specimens B.M. D. 7630) on an example of 

 Montlivahia Victories, Duncan, in the collection of the late Mr. R. F. 

 Tomes, from the zone of Liparoceras capricorniis at Cherrington, 

 Warwickshire, north-east of Moreton-in-the-Marsh, Gloucestershire, 

 Tesemble the specimen just described sufficiently to be included in 

 this species. An outline figure of one of these specimens is given 

 on PI. XIV, Fig. 6. 



Fig. 6 on Diagram I represents the specimens from the capricornus 

 zone, the same form as Fig. 5 being repeated to indicate that that 

 form passes into the higher zone unchanged. 



The following is a table of changes in the characters of this 

 species during its life-history : — 

 Ti/pe of Branching . 



At dichotomy 1 ... T^-pe I at 120°. 



,, 2 ... Type I-Intermediate tjTDe at 90°-100°. 



,, 3 ... Intermediate tj^e-Type II at 60°. 



„ 4 ... Tj-pe II at < 60°. 



^ J. "W. Gregory : British Museum Catalogue of Cretaceous Bryozoa, vol. i (1899), 

 p. 150. 



