DEUTZIA. 



[ 198 ] 



DIATOMA. 



oblique, wavy lines, arising from their being 

 twisted. In the side view of the cells, the 

 endochrome exhibits thick, frequently cleft 

 rays, corresponding in numbermththe angles. 



D. Swartzii (PI. 10. fig. 7 ; fig- 8, side 

 view of separate cell). Filament triangular. 

 Length of joint 1-2000 to 1-1660"; breadth 

 of filament 1-630". Not uncommon. Spo- 

 rangia round or oblong. 



D. quadrangulatum. Filaments quadran- 

 gular. Length of joint 1-1240"; breadth of 

 filament 1-600 to 1-450". 



BiBL. Ralfs, Brit. Desmid. p. 60; KUtz- 

 ing, Sp. Alg. p. 190. 



DEUTZIA, Thunberg.— A genus of Phila- 

 delphaceae (Dicotyledonous Plants) remark- 

 able for the stellate hairs upon their foliage 

 (PI. 21. fig. 26), and the reticulated mem- 

 brane covering the seeds, both of which struc- 

 tures form interesting microscopic objects. 

 See Hairs and Seeds. Fig. 170. 



DIACALPE, Bl. 

 — A genus of Cya- 

 thaeous Ferns, with 

 globular indusia, 

 splitting open at the 

 top (fig. I7O), and 

 containing spor- 

 anges inserted on a 

 punctiform recepta- 

 cle rising from the 

 middle of the vein. 

 Herbaceous; leaves 

 tripinnate, membra- 

 nous. Native of Java. 



DIACHJEA, Fries. — A genus Fig. 171. 

 of Myxogastres (Gasteromyce- 

 tous Fungi), consisting of pe- 

 rishable little plants, growing 

 over either living or dead plants, 

 vnth an elongated membranous 

 peridium, which falls off like a 

 cap, and displays a white reticu- 

 lated capillitium furnished with 

 a floccose central column, with 

 interspersed blackish-red spores. 



Diaclicea differs from Stemo- 

 nitis in the peridium, the colu- 

 mella, and the habit of growth. 



D. elegans, Fr. {Stemonitis, 

 Trentep.), the only species, has 

 been found in England, upon 

 the living leaves of the Lily of 

 the Valley, &c. (fig. 171). 



BiBL. Fries, Syst. Mycol. iii. 

 p. 155; Berk. Ann. Nat. Hist. 

 i. p. 257; Corda, Ic. Fung, v.^^j^-^^^ 



pi. 3. fig. 38. IJiachceaeleg 



Diacalpe asplenoides. 



Part of a pinnule with sori. 



Magnified 10 diams. 



ans. 

 Magn. 25 diams. 



DIADESMIS, Kiitz.— A genus of Diato- 

 macese. 



Char. Frustules navicular, closely united 

 into elongated biconvex filaments; valves 

 with a median and terminal nodules. Aqua- 

 tic. (Not British?.) 



The markings have not been satisfactorily 

 investigated. 



D. confervacea (PI. 12. fig. 27). Breadth 

 of frustules (in front view) about half the 

 length ; valves unstriated (under ordinary 

 illumination?), lanceolate, acuminate and 

 acute at the ends; length of frustules 1-960". 



Three fossil species. 



BiBL. Kiitzing, Bacill. p. 199, and Sp. 

 Alg. p. 95. 



DIAMOND-BEETLE. See Curculio. 



DIAPTOMUS, Westw.— Agenus of Ento- 

 mostraca, of the order Copepoda, and family 

 Diaptomidse. 



Char. Head distinct from thorax ; inferior 

 antennae two-branched ; thorax and abdomen 

 each of five segments; foot-jaws unbranched; 

 legs five pairs, the first pair with two branches, 

 one three- the other two-jointed; three suc- 

 ceeding pairs with each branch three-jointed ; 

 external ovary single, large, lying across the 

 abdomen. 



D. castor (PI. 15. fig. 38). Found in ponds 

 and slowl}^ running water ; common in spring 

 and autumn. Length about 1-8". 



BiBL. Westwood, Entomologist's Text- 

 book ; Baird, Brit. Entom. ; M. -Edwards, 

 Hist. Nat. Crust, iii. 427. 



DIATOM A, Dec— A genus of Diato- 

 macese. 



Char. Frustules (in front view) linear, 

 sometimes cuneate ; at first united into flat 

 filaments, afterwards partly separating so as 

 to remain connected by the generally alter- 

 nate angles only, and thus forming a zigzag 

 chain. 



Filaments either free or fixed by a stipes. 

 Frustules prismatic, without vitta3; valves 

 with transverse continuous striae (not resol- 

 vable into dots ?), not always visible by direct 

 light ; ends of the striae extending into the 

 front view. 



D. vulgare (PI. 12. fig. 26; a, side view; 

 b, front view). Fixed by an inconspicuous 

 stipes ; frustules rectangular, oblong ; valves 

 contracted and obtuse at the ends striae 

 evident; length of frustules 1-430". Aquatic. 



D. tenue. Stipitate; valves lanceolate, 

 striae evident; length of frustules 1-660". 

 In fresh or brackish water. Very variable in 

 the form (front-view) of the frustules ; some- 

 times cuneate. 



