94 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



1. External layer of spicules consisting of baskets, reticulated 

 bodies, or hollow plates. Feet with supporting rods or plates, 

 in some species also with end plate. Calcareous ring with 

 short tails 4 



2. External spicules consisting of small biscuit-shaped bodies with 

 4-5 holes, often one side prolonged into a sharp tooth. Feet 

 few, scattered, 5-6 in the dorsal ambulacra, 8-10 in the ven- 

 tral ones 1. Leptopentacta nova, new species 



2. External spicules consisting of rosettes. Feet fairly numerous, 

 although arranged in single rows 3 



3. Feet 24-26 in the ambulacra (in individuals 35-40 mm. long). 

 Leptopentacta i/nbricata (Semper) 



3. Feet 15-20 in the ambulacra (in individuals 40 mm. long). 

 Leptopentacta typica (Theel) 



4. External spicules consisting of simple, 4-spok:ed, deep baskets 

 with knobbed to dentate rim. Feet with numerous supporting 

 rods or plates 5 



4. External spicules consisting of complicated reticulated bodies 



or concave plates 6 



5. Buttons swollen or irregularly knobbed. Baskets comparatively 



large and delicate, with 4 marginal holes 



Leptopentacta grisea H. L. Clark 



5. Buttons predominantly strongly knobbed and regular. Bas- 

 kets small, not delicate, and apparently never with marginal 

 holes 2. Leptopentacta panamica, new species 



6. External spicules reticulated bodies^ ; feet 20-23 in ventral 



rows (in individual, 40-45 mm. long) 



Leptopentacta javanica (Sluiter) 



6. External spicules large concave plates with a varying amount 

 of reticulated bars. Inner layer knobbed buttons slightly ir- 

 regular and large reticulated plate. Feet with oblong support- 

 ing plates smooth or knobbed, with a varying number of holes. 

 3. Leptopentacta nina, new species 



3 Sluiter's figure (1880, pi. 4, fig. 10) looks suspiciously as if it belonged to 

 a Paracaudina. His description is not very clear, and in 1901, p. 79, he writes 

 "javanica with typica and imbricata," following Ludwig, 1837, p. 1221 (reprint 

 p. 5). If one can trust Semper's figure (plate 14, fig. 12), imbricata must be 

 different from javanica, as it has a simple calcareous ring. Although Ludwig's 

 "imbricata" has distinct tails on the ring, it is not proved that it is identical with 

 Semper's species or with Theel's. 



