158 CALCAEEOUS SPONGES. 



munication to the ' Neucs Jahrbuch'*, that they fully proved the position of the 

 Pharetrones amongst Calcareous Sponges. 



In the same number of the ' Neues Jahrbuch ' just referred to, there appeared a 

 lengthy article by Dr. G. Steinmann f on " Pharetronen-Studien," which professed to 

 be the results of five years' investigation of this group. Steinmann agrees with Zittel 

 as to the originally calcareous nature of the fibre and to its being composed of small 

 simple calcareous bodies, which he states are, in their present fossil condition, im- 

 bedded in a calcareous mass, but originally the mass might have been either horny or 

 calcareous. In spite of the strong resemblances which Zittel had discovered between 

 this group of fossils and recent Calcareous sponges, Steinmann concludes that " The 

 Pharetrones are an extinct independent division of the Ccelenterata, whose skeletal 

 structures partly resemble those of Sponges, partly those of Hydrozoa, and in part 

 show completely peculiar characters. A resemblance to their dermal skeleton is 

 only found in septate Corals and Hydrozoa, and the structure of their skeletal fibres 

 can only and solely be compared with that of Alcyonaria " J. As, however, within a 

 few months after the publication of the paper the author himself, in a communi- 

 cation to the ' Neues Jahrbuch ' §, withdraws his opinions, notwithstanding that they 

 had received the support of Prof. Moseley, it is not worth while to show their incon- 

 sistency with a true interpretation of the facts. 



In the 'Annals and Magazine of Natural History' for January 1883 ||, Mr. H. J. 

 Carter published " Further observations on the so-called Farringdon Sponges," in 

 which he acknowledges the relationship of many of the Pharetrones to Calcareous 

 sponges ; and he also gives a description and figures in the same paper of a recent 

 calcareous sponge possessing a skeleton of solid vermiculate fibres, composed of large 

 and small three-rayed spicules, thus distinctly similar to the skeleton of the fossil 

 Pharetrones. 



Shortly after the appearance of Carter's paper. Dr. Emil von Dunikowski contri- 

 buted to the 'Palseontographica'^ a highly important treatise on " Die Pharetronen 

 aus dem Cenoman von Essen und die systematische Stellung der Pharetronen." The 

 author fully corroborates the facts which I had already recorded** respecting the 

 spicules of the fibre of these sponges ; and he adds the further interesting discovery 

 of traces of interior canals in some of the larger spicules, the supposed absence of 

 which led Steinmann to insist that these forms could not belong to Calcisponges. 

 Dunikowski treats fully of the anatomy of the group, and finds so close a resemblance 

 to that of the recent fiimily of Leucones, Haeckel, that he includes therein the 

 Pharetrones as a subfamily. I am unable to agree with this classification, which is 

 based on the opinion that the original constitution of the skeleton is essentially 



* 1882, Bd. 2, p. 204. t Loc. cit. p. 139. t Loc. cit. p. 188. 



§ Neues Jahrbuch, 1883, Bd. 1, p. 79. || 5th ser. vol. ii. p. 20. f Band 29, 1883. 



»» Annals & Mag. Nat. Hist. 1882, 5th ser. vol. x. p. 185. 



