DESCRIPTIONS OF GENERA AND SPECIES 205 



Genus DESMOGASTEB, ROSA. 



DEFINITION. Two pairs of testes and efferent ducts opening XI/XII, XII/XIII ; 

 ovaries in XIII. 



This genus is at present only certainly known by one species, D. doriae. Its 

 anatomy has been carefully worked out by ROSA (11). The principal differences 

 from Moniligaster are indicated in the above definition of the genus ; they mainly 

 concern the doubling of the male apparatus. The sperm-ducts lie in two segments, 

 the funnel lying in the segment in front of that which bears the pore belonging to it. 

 The single spermatheca is, as in Moniligaster, to be found in segment viii. 



There is a peculiarity in the vascular system, which may, possibly, be of generic 

 value; the two last pairs of hearts those lying in segments x, xi appear to be 

 double. The outer vessel is the larger, and is sinuous in its course ; the inner 

 vessel closely embraces the oesophagus. At its origin the outer vessel, which is the 

 true heart, communicates with the inner by a short branch ; the inner vessel 

 communicates, above the oesophagus, with its fellow of the opposite side, but has 

 no direct communication with the dorsal vessel ; they end in two lateral vessels, which 

 run along the body-wall. 



(i) Desmogaster doriae, ROSA. 



D. doriae, ROSA, Ann. Mus. civ. Geneva (2 a), IX, p. 369. 



Definition. Length 500 mm.; breadth 12 mm,; number of segments, 330. Septae VII/XI, 



greatly thickened; last pair of hearts in XI; ten gizzards, commencing in XX. Had. 

 Meteleo, Burmah (1000-1400 M. in height^). 



(2) Desmogaster horsti, BEDDARD. 



D. sp., HORST, Zool. Ergebn. Max Weber, III. p. 49. 

 Definition. Length 140 mm. ; number of segments nearly 300; septa VII/X thickened; 



eight gizzards, commencing in XVII. Hal. Sumatra, Mt. Singalay. 

 This appears to me to be a distinct species, by reason of the fact that it has 

 only eight, instead of ten, gizzards. HORST also mentions that the sperm-ducts 

 do not open into the spermiducal glands at their summit, as is the case with 

 D. doriae. HORST IB inclined to think that the tenth septum is absent. 



