Fig. 37 in New Taxa And Cryptic Species Of Neotropical Snakes (Xenodontinae), With Commentary On Hemipenes As Generic And Specific Characters

Fig. 37. Diagrams of the braincase, with parietal bone attached, showing the pathways of trigeminal and facial nerve branches. A. Ctenosaura, a generalized lizard (after Oelrich, 1956, and a specimen from Carolina Biological Supply Co.). B. An alethinophidian snake (simplified and composite, but essentially as in Python). Abbreviations: bp, basipterygoid process; cr, communicating ramus between levator bulbi nerves and palatine ramus of the facial nerve; lbm, levator bulbi muscle (retractor arcus palatini and retractor vomeris muscles in snake); PA, parietal bone; vn, Vidian nerve in strict sense of mammalian anatomy, formed from conjoined palatine ramus of facial nerve and levator bulbi (deep petrosal) nerve; V1, deep ophthalmic ramus of trigeminal nerve; V2, maxillary ramus of trigeminal nerve; V3, mandibular ramus of trigeminal nerve; V41b, levator bulbi nerve (probably homologous to the mammalian deep petrosal nerve); V41p, levator pterygoideus nerve; V4pp, protractor pterygoideus nerve; VIIh, hyomandibular ramus of facial nerve; VIIp, palatine ramus of facial nerve (homologous to the greater superficial petrosal nerve of mammals).