NATURAL SCIENCES OF PHILADELPHIA. 



75 



succeeding ones. The last or largest cell is more of a conical form. 

 The interior structure was faintly yellowish or nearly colorless. 

 A specimen of eighteen cells was |th of a line long, with the last 

 cell about ^ s th of a line in diameter. 



An interesting Rhizopod, not pertaining to the Polythalamous 

 foraminifers, to which my attention was directed by Prof. Verrill, 

 frequently occurred in the mud dredged off the Connecticut coast. 

 The same creature is referred to by Prof. Verrill in the Report 

 of the Commissioner of Fish and Fisheries for 1871 and 1872, page 

 503, as being extremely abundant in the clear siliceous sand 

 dredged from Vineyard Sound. 



The creature was discovered by Dr. Sandahl in the Bohnslaiis 

 Archipelago, and is described in the Ofvers. K. Vetensk. Ak. 

 Foi-h., Stockholm, 1857, 301, under the name of Astrorhiza limi- 

 cola. It is also referred to in Thomson's " Depths of the Sea," p. 

 75, as occurring in the Atlantic ooze off the Faroe Isles. 



The case of this Rhizopod is constructed of angular particles of 

 quartz-sand, cemented by tenacious matter mingled with the finest 

 dark-colored mud. The body of the case is discoid or lenticular, 

 with a number of short cylindroid processes radiant from the 

 margin, giving the case altogether an irregular stellate form, as 

 represented in the accompanying wood-cut. 



Sandahl describes the shell as exhibiting scattered yellowish- 

 brown spots, unequal, irregular, and somewhat shining. These 

 spots, in the specimens examined by me, are due to the translucent 

 quartz particles through which the yellowish color of the interior 

 soft structure of the animal is seen. Sandahl gives the number 

 of radii from 10 to 15, and the size of the case from 3 to 4 lines. 

 Our specimens measured from 2^ to 4 lines, and exhibited radii 

 from G to 13 in number. 



The interior soft substance of the little mud stars is a viscid, 



mucoid matter. The ectosarc 

 is colorless. The entosarc was 

 granular and yellowish, some- 

 times containing ova-like bod- 

 ies, with darker yellow or 

 orange-colored contents. Be- 

 sides these the entosarc con- 

 tained clear globules and a 

 multitude of diatomes, princi- 

 pally a species of Coscinodis- 

 cus. 



I failed to see the Astro- 

 rhiza in a very active condi- 

 tion, probably from the hot 

 summer weather too quickly 

 giving rise to decomposition in 

 the material collected. Only in 

 two instances did I discover 



Astrorhiza limicola, magnified ]<> diameters. 



