278 



Malacosoi/ia, which latter term was already used by Hübner in 1S16 for a genus of Lepidoptera 

 (and by Chevrolat in 1S34 again for a genus of Coleoptera). 



Alcock referred this genus doubtfuUy to the Pinnotherelinae, but it certainly belongs 

 to the present subfamily. 



The only known species is : 



I. Hapalonotus reticulatiis (de Man). PI. 18, Fig. 3. 

 1879. Malacosoma reticulatuvi de Man. L. c, p. 67. 



This remarkable species has been never found back since its first discovery, although 

 numerous collections were made afterwards at the very locality (Amboyna), where it was originally 

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

 opportunit)' to make it better known, especially because no figure of it has been pubHshed. 



At first sight the animal presents the outer aspect of a very large Pinnotheres : the 

 carapace is globular, membranaceous, and Httle 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 visible, 

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

 very characteristic reticulating meshes, bordere cl b}- thick anastomosing 

 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 century. There are nowhere any granules on the surface 

 and the various regions are ill defined : on the gastric region we observe two transverse, oval 

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

 region : there are two branchio-gastric or branchio-cardiac erooves, 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 fronto-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 observe a fine groove running straight 

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

 and pterygostomian regions and proves to be the pleural groove, ending at the antero-external 

 angle of the buccal cavity. 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 very short, consisting of only two joints, 

 but perhaps broken oft' (fig. 3^'). Epistome present. Side walls of cephalothora.x, like the 

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



130 



