NO. 3 DEICHMANN: HOLOTHURIOIDEA ; PART I, DENDROCHIROTA 85 



The type species seems to be the only representative known from 

 West Indian waters, while P. calcigera (Stimpson) is widespread in the 

 northern Atlantic and Pacific oceans, and 7 related species have devel- 

 oped along the western coast of North America (see Deichmann, 1938). 



From the Panamic region (and Chile) 4 species are known. One of 

 these is closely related to the type species. 



Key to the Species of Pentamera Known from the Panamic 



Region 



1. Spicules in skin acorn-shaped bodies, possibly derived from 

 tables. Feet with end plate and curved supporting tables with 



well-developed spire. Color white 



1. Pentamera zacae Deichmann 



1. Spicules in skin 2-pillared tables or derivatives of these (with 

 spire reduced to knobs or spines) 2 



2. Spicules scattered, tables reduced to disks with spinous edge 

 and mostly with 2 knobs or spines indicating the spire. Feet 

 with large end plate and a few spectacle-shaped rods, rarely 



any trace of a spire. Color dark brown to black 



3. Pentamera chierchia (Ludwig) 



2. Spicules crowded tables with well-developed spire, disk with 

 smooth edge. Feet with end plate and supporting tables with 

 well-developed to excessively developed spire 3 



3. Supporting tables in feet partly with excessively tall spire. 

 Tables small 2. Pentamera beehei Deichmann 



3. Supporting tables in feet with moderately tall spire. Tables 

 not small 4. Pentamera chiloensis (Ludwig) 



1. Pentamera zacae Deichmann 

 Plate 12, Figs. 10-17 



Pentamera zacae Deichmann, 1938, p. 375, text fig. 9. 



Diagnosis. — Small form (few cm. long) body strongly curved, taper- 

 ing toward both ends. Feet cylindrical, non retractile, in 5 bands, most 

 numerous on the ventrum, more scattered on the dorsum and toward the 

 oral and anal ends. Spicules a crowded layer of peculiar small bodies re- 

 sembling acorns, with a tapering spire, mostly composed of 2 rods and a 

 basal cup-shaped part. Feet with large end plate and numerous support- 



