130 Transactions of the Society. 



Bilfinger, L. — Zur Eotatorienfauna Wiirttenibergs. Zweiter Beitr. Jaliresh. 



d. Ver. f. vaterl. Nat. i. Wiirtt., 50. Jahrg., 1894, p. 53. 

 Weber, E. F. — Faune Botatorieime du Bassin du Leman. Geneve, 1898, 



p. 549, pi. 20, figs. 26-8. 



Spec. Cliar. — Body elliptical, gibbous dorsally, flat ventrally, 

 showing slight dorso -ventral compression ; head sub-conical ; neck 

 a marked constriction ; face sub-prone, protruding in a very marked 

 beak-shaped projection of buccal orifice ; lorica somewhat flexible ; 

 dorsal cleft well marked ; lateral cleft well marked ; eye cervical, 

 single ; foot short, stout, tapering, terminal, not ventral ; toes more 

 than \ length of rest of body, furcate, style-shaped, well decurved ; 

 incus very long. 



Gosse's description is very weak, and the figure errs in accen- 

 tuating the angles of the lorica ; and it was with some difficulty 

 that we satisfied ourselves about the identification of this species. 

 But from his drawing of Hooclii and his description of what he 

 <jalls the bird's beak in ramphigera, and his reference to the length 

 of the incus, especially of the fulcrum in both, we are satisfied 

 that his two species are one, and that we have it here, and that the 

 name Hoodii must take precedence of ramphigera. 



Tessin-Biitzow described this species as Plagiognatha gracilis, a 

 name which is unavailable owing to Furcularia gracilis Ehr., which 

 is certainly to be included with this species in the genus Diaschiza. 

 His (T.-B.'s) description is also lacking in detail, and he makes 

 the same mistake about the beak -like process. 



This beak-like process is one of the most marked features of 

 this species. It is strange that Gosse, Tessin-Biitzow, and Weber 

 (sub D. valga) should fall into the error of taking it for a projec- 

 tion of the trophi, whereas it is absolutely distinct from the jaws, 

 and consists of the extended lips of the buccal orifice. Bilfinger 

 and Weber (loc. cit.) also make the mistake of naming this species 

 D. valga, while their figure and descriptions are certainly those of 

 D. Hoodii. Of this we shall have more to say under D. valga at 

 the end of this monograph. 



This is one of the placid species of the genus, like D. ventripes, 

 and prefers creeping about the flocculent matter found on water- 

 weeds to swimming. 



It never, so far as our observations go, throws its toes over its 

 back, and, in fact, does not contort itself so much as the other 

 species do, owing to the slightly stiffer texture of its lorica. 



The dorsal cleft, which is well marked, gapes posteriorly. 



The cervical eye lies at the extremity of the large brain-sac, 

 and is a single red pigment-spot without a lens. 



The foot is terminal, not ventral, and carries the usual setae 

 situated on a small papilla, and generally four in number. It 

 tapers rapidly to the last pseudo-joint, which is of fair length, and 

 only slightly wider than the combined bases of the toes. 



