278 



Malacosoma, which latter term was already used by Hubn-er in iSi6 for a genus of Lepidoptera 

 (and by Chemioi_\t in 1834 again for a genus of Coleoptera). 



Alcock referred this genus doubtfully to the Pinnoiherelinae. but it certainly belongs 

 to the present subfamily. 



The only known species is: 



I. Hapalonotus reticulatus (de Man). PI. iS, Fig. 3. 

 1879. Malacosema reticulatum de Man. L. c, p. 67. 



This remarkable species has been never found back since its first discover\\ although 

 numerous collections were made afterwards at the verj- locahtj- (AmbojTia). where it was originally 

 found. The only known specimen (a Q) is still preser\-ed in the Leiden Museum and I take this 

 opportunitj- to make it better known, especially because no figure of it has been published. 



At first sight the animal presents the outer aspect of a ver}- large Pinnotheres: the 

 carapace is globular, membranaceous, and little broader than long; the lateral margins are 

 greatly rounded and inflated, especially the anterior ones. In the anterior part the carapace 

 is nearly straight transversely, but it is much more vaulted posteriorly, across the branchial 

 regions. In lateral aspect of the animal the anterior portion of the carapace, with the front, 

 is nearly perpendicular, but in dorsal view the anterior margin of the latter is just xnsible, 

 together with the small and thick eye-peduncles. The whole carapace is covered bj- 

 verv characteristic reticulatinor meshes, bordered bv thick anastomosingr 

 lines of a brown colour and remarkably symmetrically distributed; this 

 pattern has apparently lost nothing of its strength, notwithstanding the animal's being preserved 

 in alcohol during more than half a centun". There are nowhere anv sranules on the surface 

 and the \-anous regions are ill defined: on the gastric region we obser\'e two transverse, oval 

 pits, each of them connected by a groove to a similar depression in the middle of the hepatic 

 region : there are tvio branchio-gastric or branchio-cardiac grrooves, but there is no cervical 

 sulcus between them, and the intestinal region is faintly outlined. 



The front is regularly arched, its anterior margin is thickened and faintly bilobed in 

 the middle. Orbits small and shallow, filled by the short, globular, movable eye stalks, eyes 

 distinct, black. The fi-onto-orbital distance measures nearly half the greatest width of the cara- 

 pace. As has been said the lateral margins, especially anteriorly are rounded and inflated, 

 posteriorly they are not at all indicated, but here we obser\-e a fine onroove runningr straight 

 to the implantation of- the last pair of legs ; this line is continued forward on the subhepatic 

 and pter\gostomian regions and proves to be the pleural groove, ending at the antero-e.xtemal 

 angle of the buccal ca\nt)-. Posterior margin of carapace nearly straight, strongly rimmed and 

 equal in length to base of front. 



Antennulae robust, folded transversely in rather incomplete fossae. Antennae extremely 

 small, second joint of peduncle quadrate, flagellum ver>- short, consisting of only two joints, 

 but perhaps broken off (fig. 3 a). Epistome present. Side waUs of cephalothorax. hke the 

 carapace, entirely smooth and glabrous, except of course at the entrance of the afferent 



