ì'òi) 



V. SILVESTRI 



illustratione carente, inceituin est utrum in familia Polyzonidae an Platy- 

 desmidae continendum. Descriptio haec est : The creature (Cryptodesmns 

 Getschmannii) is only about three times as long as broad ; it is as strongly 

 depressed as the African Cryptodesmi, and the head is entirely concealed. 

 This is, however, anotlier of the curious resemblances in form between 

 Diplopoda really not related. Cryptodesmns Getschmannii belongs to the 

 Polyzonidae. The specimen is a dried female and may be young. The poste- 

 rior end of the body is somewhat rolled under, and the head is so pressed 

 against the first segment that the presence or absence of eyes cannot be 

 certified. The relationship is with Polyzonium in the shape of the head, 

 antennae and legs, also in the structure of the segments and the lack of 

 dorsal ornamentation. The pores are located nearly as in Polyzonium and 

 arc in the continuous series. From Polyzonium there is, however, so great 

 a difference in the proportions of the body and of the short, strongly de- 

 pressed segments, that the species is the type of at least a new genus, for 

 which Platyzonium would be an appropriate name. The condition and sex 

 of the only specimen make a satisfactory study impossible, but the fact 

 that the head is less pointed than in Polyzonium, and is much exceeded 

 by the first segment, would seem to indicate that other differential cha- 

 racters may be expected from the examination of better material. 



Fam. PLATYDESMIDAE Saussure 1800. 



Caput subglo] aliare. Oculi praesentes vel nulli. Antennae arti- 

 culis subaequalibus. Mandibulae (Fig. D) degenerantes articulis 

 duobus compositae, quorum alter apicalis, attenuatus dentibus 

 nonnuUis, parvis armatus. Hypostoma : maxillae seiunctae appen- 

 dice singula auctae (Fig. 10) vel non (Fig. 11), galeae parvae, 



l-'ig. 9. Fig. 10. Fig. 11. 



infrainaxillare elongatuni , integrum, basilare forma normali, 

 cardines praesentes. Scuta })l('uralia cum tcrgitis coalita. Laminae 

 pedigerae liberae. Medium dorsum sutura manifesta. Tergitum 



