DUliLIN MICROSCOPICAL CLUB. 343 



H. "W. Mackintosh exhibited a cross section of the spine of 

 Phjllacanthus laculosa ; the only difference that he could detect 

 — beyond mere colour and size distinctions — between it and the 

 spines of P. annulifera was in the character of the central net- 

 work, which was circular and sharply defined, and had compara- 

 tively slight solid rods in the latter, whilst in P. haculosa it was 

 irregular in outline and much less distinctly marked off from the 

 surrounding tissue and had thick solid rods. 



Puccinia Smyrnii, Corda, on same leaf with an ^cidium, 

 exhibited. — Mr. Greenwood Pirn showed Puccinia Smyrnii, Corda, 

 in the TJredo-condition accompanied on the same leaf by the sper- 

 mogonia of (apparently) an -3j]cidium, and suggested the query as 

 to whether their occurrence together had any bearing on the 

 statements that Puccinia and ^cidium are different stages of the 

 same plant. This species which is described as rare in Cooke's 

 Manual appears to be abundant in many parts of the Co. Dublin, 

 wherever Smyrnium oliisatrum occurs. 



A form of Coscinodiscus, probably G. apiculatus, Ehrenb., 

 exhibited. — Rev. Eugene O'Meara exhibited a form of Coscino- 

 discus found by him in the stomach of ascidians dredged in the 

 neighbourhood of Kinsale. Upon first inspection it might be 

 regarded as identical with Coscinodiscus perf or atus, Ehrenb., but 

 a closer examination presented characters very distinct from 

 those of the species named. The areoles surrounding the hyaline 

 boss are much smaller and more numerous, and are generally 

 more decidedly hexagonal than in C. perforatus and more closely 

 arranged and moreover they increase in size towards the margin. 

 Mr. O'Meara considered this form to be likely identical with 

 Coscinodiscus apiculatus, Ehrenb., * Microgeologie,' t. xvii. f. 43. 



Plagiophrys spherica. Clap, et Lachm., exhibited, and remarks on 

 the so-called G) omia granulata, Schulze, and on the form referred to 

 by latter author {erroneously), as Microgromia socialis (Archer), 

 Hertwig et Lesser. — Mr. Archer showed living examples 

 of the Monothalamatous llhizopod he had referred to Plagio- 

 phrys spherica. Clap, et Lachm., a form which however 

 Hertwig and Lesser seemed inclined to suppose not to be pre- 

 cisely that species. Be that as it may it was surely at least a 

 form of the genus Plagiophrys, but strange to say this or one 

 very like it seemed to be referred to the genus Gromia, (Dujar- 

 din), by Prof. Eilhard Schulze under the name of Gromia granulata 

 (Schultze's ' Archiv f. mikr. Anat.,' Bd. xi, p. 117, t. vi, f, 5,6), 

 from which genus it would appear altogether distinct in appear- 

 ance and habit and behaviour. I£ Mr. Archer had erred (and if 

 80 it was not very far) in placing his Gromia socialis to that 

 genus (now made the type of a new one by Hertwig and Lesser, 

 under the name of Microgromia), surely still more had Prof. 

 Schulze erred in placing a form like that now exhibited thereto. 

 The allusion to Microgromia socialis (A.rcher), Hertwig and Lesser, 

 suggsted to Mr. Archer to mention that he thought there could 



