274 86 



Weber (1898, p. 580) describes the male as follows: 



"Le male est morphologiquement identique à la femelle. Il est seulement plus délicat, 

 de taille plus petite et ne possède pas de tractus intestinal. Les organes excréteurs du mâle 

 sont aussi développés que ceux de la femelle et les canaux latéraux se déversent dans une 

 vessie contractile. Le système nerveux, les tentacules et l'organe sacciforme ont la même 

 structure que chez la femelle. La cavité du corps est occupée en grande partie par un longue 

 testicule piriforme. Le penis est court, mais de structure normale. Les glandes prostates sont 

 bien développées. La musculature et les organes excréteurs sont faciles à étudier chez le mâle, 

 à cause de la grande transparence du corps et de l'absence de système digestif." Size of 

 female 290— 380/*, of male 260 /i. 



Description. Form of the body the same as that of the female, carapace 

 too almost in full accordance, onlj' a little more hyaline; on the dorsal shield some 

 crests make a peculiar figure which will be better understood when studied in Tab. V, 

 fig. 5; the dorsal antenna is situated where two well marked lines meet each other 

 in the middle lines of the body; laterally, a little from the two posterior corners of 

 the dorsal shield, the two lateral antennae are found (Tab.V, fig. 5). Ventral plate in 

 the male somewhat larger than in the female ; the excavation of the anterior border 

 not so deep as in this sex; foot three-jointed, but when compressed and when the 

 penis is protruded, the segmentation inconspicuous; toes long, well-developed; in my 

 specimens broader than those which are drawn by Cohn. I have been unable to 

 find conspicuous foot glands, well-developed in the female sex; also the long tactile 

 hairs seem to be wholly absent. The wheel-organ is highly developed; it consists 

 of a strong ciliary wreath, most probably interrupted dorsally and ventrally; laterally 

 two rather inconspicuous ears; on the disc a median furrow, covered with cilia, 

 terminating in a strong tuft; laterally three pairs of prominences covered with cilia; 

 the two pairs nearest to the fuiTow; one pair more laterally. The two pairs which 

 are nearest to the median furrow, carry a series of taps, each with a long hair. I 

 have been unable to find the papillæ of the female, mentioned by almost all authors 

 from recent times, and which de Beauchamp has shown carry the openings of the 

 retrocerebral organ. All in all the wheel-organ of the male resembles that of the 

 female very much. I especially refer the reader to Weber (PI. XXI, fig. 21); it is 

 highly interesting, that also in the male we are able to point out the cilia-covered 

 furrow which in the female leads into the mouth, and which may be regarded as 

 closed in the male. 



The retrocerebral organ is very large, reaching almost to the middle line of 

 the body; as I have never been able to get a side view of the male, I have not 

 been able to find out if it sends a cul de sac downwards between mastax and brain; 

 the opening outwards I have not been able to see; the organ is filled with numerous 

 aréoles which show a polyhedrons structure, caused by pressure. According to de 

 Beauchamp they derive from the protoplasmatic layer in the bottom of the sac 

 which is due to a vacuolisation of the protoplasma. I refer the reader to the admir- 

 able investigations of de Beauchamp (1909, p. 127). Above the organ is the red eye 

 with a conspicuous lens. On either side of the sac are some large piriform cells 



