PLATE XXVI. 



The figures of this Plate were painted by me from living specimens in the Canary Island Lanzerote, 



December 1866. 



Figs. 1 3. Alophota giltschiana, n. sp. (p. 348). 



Diam. 



Fig. 1. A young larva (Cystonula) 2 to 4 mm. in length. The complete body represents a single 

 medusome, the modified umbrella of which is the pneumatophore (pf), the manubrium is the 

 siphon (s). From the pedicle of the siphon (or the incipient trunk, a) arises a tentacle (t). 

 The inside of the siphon bears hepatic villi (so), and its terminal mouth forms a square 

 suctorial disc (ss). The apex of the float opens by a stigma (po), . . ■ . x 20 



Fig. 2. An older larva 8 mm. in length. The trunk (a) of the small corm encloses an ovate pneu- 

 matosac (pf) in its apical half, and bears the primary siphon (or protosiphon, sv) on the 

 distal pole of the sub-horizontal main axis. From the middle third of its ventral side arise 

 three small cormidia, each of which is composed of a secondary siphon, a palpon, and a 

 tentacle ; po, apical stigma, . . . . . . . . x 8 



Fig. 3. A mature corm of Alophota giltschiana, seen from the right side. The pneumatocyst (pf) 

 fills the greatest part of the vesicular trunk, po, The apical stigma (on the anterior end). 

 The basal (or posterior) end of the trunk bears the primary siphon (su) with a palpon and a 

 tentacle ; so, mouth of siphon. The ventral side of the trunk bears an ordinate series of five 

 cormidia, each composed of a secondary siphon (s), a palpon (to), a tentacle (t), and a 

 gonodendron (g), . . . . . . . . . . x 4 



Figs. 4-8. Arethusa challenge?^, n. sp. (p. 349). 



Fig. 4. Lateral view of a mature corm, from the right side. The oblongish pneumatosac (pf) fills 

 only two-thirds of the vesicular trunk, po, Apical stigma. The sterile protosiphon (su), at 

 the basal or distal pole of the horizontal axis, is separated by a group of small palpons 

 from the ventral series of fertile metasiphons ($) ; the larger of these bear on the right side 

 a rose-coloured gonodendron (g), . . . . . . . . x 2 



Fig. 5. Lateral view of a larger corm, in a much contracted state, from the left side. The pneumatosac 

 (pf) strongly contracted, with an annular constriction, expels gas through the apical 

 stigma (po). The numerous tentacles are spirally coiled up, ... nat. size 



Fig. 6. A single cormidium, isolated. The simple common pedicle (ap), arising from the ventral side 

 of the trunk, bears a large tentacle (t), with a basal ampulla (to), a clustered gonodendron 

 (g), and a contracted siphon with four segments ; sp, siphonal pedicle ; sb, basigaster, sv, 

 stomach with black hepatic villi; sr, proboscis; so, mouth, . . . . x 10 



Fig. 7. A very young tentacle (t) with its basal ampulla (to), . . . • . x 40 



Fig. N. A. single branch of a gonodendron. gs, Gonostyle ; q, gonopalpons ; //, androphores (male 



medusomes) ;/, gynophore (female medusome), . . . . . . x 20 



