Miscellaneous. 137 



The observations of F. E. Schiiltze on Quadrula symmetrica, and 

 those of Leidy on Trincma acinus, show that in these two genera 

 the same things evidently take place as in Eiighjplm ; that is to say, 

 the platelets protecting the body are produced in the interior of 

 the parent individual, and afterwards conveyed round the body of 

 the daughter individual. M, Gruber has almost completely traced 

 these same phenomena of division in Cyphoderia cnnpuUa, the cara- 

 pace of which is not formed of a comparatively restricted and toler- 

 able constant number of plates, but rather of an infinity of little 

 particles which gives this envelope the aspect of shagreen. 



The phenomena of division seem to be nearly the same in the 

 A7'ceUa'. 



In the Monothalamia with carapaces formed of foreign materials, 

 such as the Dijfliif/ice, which are covered with grains of sand &c., 

 individuals have been observed united by their buccal poles ; and 

 this state has been regarded as the result of conjugation. According 

 to Dr. Gruber this interpretation is incorrect, and the individuals 

 thus joined must be the product of a division on the point of com- 

 pletion. With Biitschli he assumes that these Ehizopods first of all 

 introduce into their bodies the foreign substances which are to serve 

 for the formation of the envelope. The sand-grains, Diatoms, &c. 

 are then transported to the outer surface of the newly-formed indi- 

 vidual, just in the same way as the platelets of the Euylyphce, 

 Quadridce, &c. 



The forms which are protected by an inflexible chitinous carapace 

 also present the same mode of multiplication. This would seem to 

 be proved by Dr. Gruber's observations on Microgromia socicdis, and 

 Schneider's on Diff-vgia inchelys. 



On the other hand, in the genera which have an envelope formed 

 by a flexible membrane adherent to the sarcode of the body, divi- 

 sion takes place, as in the Amadxe, in the mode that may be denomi- 

 nated normal, because it is that which is by far the most frequent 

 in animal cells. A constriction is produced in the middle of the 

 body, and causes the formation of two individuals.^ — Zeitsclirift f. 

 u'iss. ZooL XXXV. p. 431, & xxxvi. p. 104 (1881) ; Bill. Univ., 

 Archives cUs Sciences, December 15, 1881, p. 624. 



The Mediterranean Species of Fierasfcr. By Prof. C. Emeky. 



Fierasfer acus, the commonest species in the Mediterranean, 

 attains a length of lU centim. (about 7| inches), and takes up its 

 abode preferently in the large Holothuria?, such as Holotharia tubu- 

 losa and Stichopus regulis. The author has frequently observed the 

 process adopted by the little fish for introducing itself into the body 

 of the Echinoderm. It commences by examining tlie whole length 

 of the latter until it has discovered at which end the anus is situ- 

 ated. It places its muzzle against this orifice, and then, at the 



Ann. & Mag. N. Hist. Ser. 5. Vol. ix. 10 



