"Derivation" of Gibocellum 73 



whilst in Phalangium they are united as far as about the end of the fourth pair of coxae, 

 according to Tulk (PI. Y., fig. 38). 



Stacker could not know that the supposed eyes in Cyphophthaliiins really are orifices 

 of odoriferous glands ; he therefore ascribes to Gibocellum the glands of this kind existing 

 in Phalangium, but places their openings, not, as in Phalangium, above the ends of the coxae 

 of the first pair of leg.s, but above the base of the antennae (chelicerae). 



It is also fi-om Phalangium that the sexual organs of Gibocellum were borrowed, Stecker 

 being unfortunate enough not to discover that what Joseph had figured as the penis of 

 Cyphophthalmus was really an ovipositor. 



For its respiratory organs Gibocellum was indebted partly to Phalangium, partly to 

 Chelonethi. The tracheas which take their origin from the first pair of spiracles are (according 

 to PI. XVIII., figs. 2 and 3; PI. XX., fig. 4) supplied with spiral thickening as in Pha- 

 langium and {b, p. 339) are even more ramified than in the latter. The course of the main 

 trunks resembles to a certain extent Tulk's figure of those in Phalangium (PL IV., fig. 33) ; 

 but the two tracheal trunks are represented as united into a single trunk for a con- 

 siderable distance, whereby Gibocellum would differ not only from Phalangium but also, we 

 should think, from all other Condylopoda — a point which Stecker has not noticed. According 

 to his description Gibocellum would agree with Chelonethi not only in having two pairs of 

 spiracles, but more especially because the tracheae, said to start from the posterior pair of 

 spiracles in Gihocellum, exhibit the same arrangement as those with the same starting-point 

 in certain Chelonethi. The arrangement, be it understood, is that which Stecker imagined 

 these tracheae in Chelonethi to present, viz. 1°, that the tracheae in question are neither 

 ramified nor furnished with spiral thickening ; and 2°, that they have no common trunk, 

 each of them taking rise' from an opening in the spiracle which is perforated like a 

 sieve (6, pp. 338, 339). The first of these alleged peculiarities in Gibocellum would imply 

 that this animal possessed tracheae of two different types^, which would be a unique case 

 amongst Arachnida ; the second peculiarity implies a morphological impossibility unless a 

 gi-eat number of spiracles were collected into a small space — a feature which would be without 

 a parallel amongst Condylopoda. 



Tulk had misinterpreted a portion of the Malpighian tubes as salivary glands (p. 429 ; 

 PL IV., fig. 18), and accordingly Stecker endows Gibocellum with a pair of tubiform salivary 

 glands (b, PL XIX., h). 



These complete the list of the organs transferred from Phalangium to Gibocellum. 

 Besides these, Stecker furnished Gibocellum with spinning organs, the position of which, 

 according to Stecker's opinion (b, p. 328), agreed with what he (at any rate when he wrote 

 that particular page) believed to be the case in Chelonethi. The fact is that Menge (p. 14) 

 had come to the result that Chelonethi possessed spinning glands, of which the spinnerets 

 were near the anterior extremity of the abdomen, either in front of the sexual orifice (in 

 Chelifer, Cheiridium and Chenies), or behind it (in Obisiuyn and Chthoniusy. Stecker having 



' Or in Stecker's own words, "To each little tube corre- Kicinulei. 

 spends an opening in the closing valve, which is perforated ' According to Croneberg (p. 455) the indications of Menge 



like a sieve." were erroneous, the glands in question being in reality 



- With regard to this point we refer our readers to the accessory to the sexual organs. It may be added that later 



considerations on the two different tj^pes of tracheae in on it was proved by Bertkau and Croneberg that the spinning- 



Arachnida, which will be found below in our description of glands of the Chelonethi in reality open on the antennae. 



s. 10 



