558 



SYSTEMATIC HISTORY OF THE INFUSOEIA. 



A glandular body and hyaline globules are seen in the internal soft sub- 

 stance near the posterior end. In moving, the position of the shell may be 

 perpendicular, or oblique to the sm^face of reptation : the hexagonal depres- 

 sions are indistinct but large. The shell fractures along the lines of junction 

 between the hexagons. 



Along with the preceding genera, Schultze, as before stated, includes in the 

 division Monothalamia the new genera Lagynis, Sq^iuxmulina, and Cornu- 

 spira. 



Genus LAGYNIS (Schultze). — Shell membranous, elastic, retort-shaped; 

 body colourless, transj)arent ; foramen large, but the j)rocesses few, very fine, 

 occasionally branching. 



It forms the type of the family LagjTiida. 



Lagynis haltica. — The transparent 

 contents rarely fill the shell, but leave a 

 space posteriorly, into which they send 

 processes which converge towards the 

 summit of the concavity of the posterior, 

 rounded extremity. OOo'". Baltic Sea. 



The form of the shell approaches that 

 of JEuglypha (?) curvata, described by 

 Pertv^, and found in an empty state by 

 him on the Simplon, at an altitude of 

 4000 to 5000 feet. 



Genus SQUAMULINA (Schultze). — Shell calcareous, plano-convex, or 

 lenticular ; adherent by the plane surface ; cavity single, one large opening 

 on the convex side ; no pores. 



Squamulina IcBvis. — Ii'regularly cir- 

 cular; much flattened; convex portion 



thick and smooth, the flat portion very 

 thin and scarcely separable from the ob- 



ject to which it adheres. The yellowish 

 animal protrudes numerous processes 

 from the excentric foramen. Largest 

 diam. 1-26'". Sea- water, Ancona. 



Genus COllT^USPIEA (Schultze).— Shell calcareous, spiral, like a Pla- 

 norbis shell ; solid or finely porous ; discoid ; symmetrical, i. e. with both sides 

 alike ; cavity single. One large foramen at the termination of the spii'al. 



dually larger towards the termination of 

 the spiral ; as many as seven tm-ns seen. 

 On the coast of Mozambique. 



D'Orbigny's OpercuUna inserta is pro- 

 bably the same form. The SpinUwa de- 

 scribed by Ehrenberg is somewhat like, 

 but is probably only a young Miliola. 



CoRNUSPiHA planorhis. — Shell trans- 

 lucent, browTi, without pores; six or 

 perhaps more turns of spiral seen. Mud 

 from the coast of Mozambique and 

 Trieste. 



C. perforata. — Finely porous, hyaline, 

 colourless \ pores cii'cular, becoming gra- 



Genus CADIUM (Bailey) (XXII. 19).— Shell silicious (chitinous ?) ovoid; 

 elongated as a sort of neck, which is bent upwards and outwards, terminated 

 by a circular foramen. 



This genus was instituted by the late Dr. Bailey, of New York, to include 

 some empty Ehizopodous shells met with in the soundings taken in the gulf- 

 stream. {SiUiman's Journ. xxii. 1856.) 



Cadium marhmm (xxii. 19).— Shell 

 marked by numerous meridian lines, of 



which about 12 are visible at once, 

 Leng-th 2-1000" ; diam. I^-IOOO". 



Sub-group ACTIXOPHEYIXA. (Part 1. p. 243.) 



(XXIII. 24-37.) 



A sub-class of Ehizopoda having a more constant and definite form, and 

 furnished with long tapering retractile filaments or tentacles, which serve 

 as prehensile organs, in the place of the usual varial)le processes of the class. 



