Misce Ilaneuius. 1 U.' » 



and which has no resemblance to the sternal lip of the larger 

 Arachnida. 



These generalities upon the anatomy of the Gamasidse show how 

 much justification we had to regard this family as the first in the 

 order Acarina, and as establishing the transition between the class 

 Arachnida and that of insects. — Comptes Hernias, December 6, 187o, 

 p. 1135. 



On the Presence in existing Seas of a Type of Sarcodaria of the 

 Secon'Iary Formations. By M. P. Fischer. 



Thirty years ago Qucnstedt noticed *, under the name of Dendrina, 

 some excavations of unknown origin observed by him in the most 

 superficial layers of the BeJemuitelliv of the Chalk. These were so 

 imperfectly defined that the German author questioned whether they 

 were not due to a morbid alteration of the test of the Belemnitellce. 



The Dendrinre of Quenstedt remained long comparatively un- 

 -known. Morris approximated them to the Tal2mice, which I 

 regard pro\'isionally as perforations of fossil Bryozoa or Hydrozoa ; 

 Pictet and other palaeontologists attributed them (I do not know 

 why) to Annelids ; Etallon established a distinct order for these 

 excavations, and thought he could describe several species of 

 Dendnna from the Jurassic formations, species characterized solely 

 by the general form of the perforations. 



By examining the Dendrince of the test of Belemnitella, I ascer- 

 tained, by means of solution of carmine, that there existed a manifest 

 osculum at which each Dendrina opened, and that these oscula were 

 not without resemblance to the efferent orifices or proctidcs of the 

 sponges of the genus Cliona. It was therefore probable that the 

 Dendrince, were related to the sponges. 



An unexpected discovery has just furnished fresh materials for 

 the elucidation of this question. Shells dredged at a depth of 

 25-90 fathoms in the Bay of Biscay showed perforations of existing 

 animals which I could not but regard as allied to those described 

 in the fossil state by Quenstedt. Soon afterwards the same fact 

 i-ecurred in shells from the Mediterranean and the Indian Seas, 

 and I acquired the certainty that the Dendrince still exist in 

 nearly all the seas of the globe, and that they present the same 

 characters and have the same perforating habits as those which 

 riddled the fossil shells of the Secondary formations with their 

 perforations. 



If we examine with a Ions the outer surface of some coloured 

 shells (Pecten, for example), small, opaque, irregular, lobulated 

 whitish spots may be observed ; these are D,'ndrin"'. A rounded 

 orifice terminates a tolerably wide oblique canal, and forms a com- 

 munication between the exterior and the cavity of the perforating 

 animal. The orifice is single, and resembles the large oscula or 

 efferent apertures of the Clionce; the lobules also are probably in 



* Petrefactenkunde Dcutschl. Cephal. Taf. xxx. fig. 3(3, 



