288 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



described as brevi pinna by Hartlaub are all similarly young and undeveloped. All that 

 can be said about them is that they appear to belong to at least two varieties. 



It is by no means always possible to identify a given specimen with one or other of 

 these varieties, for it may be intermediate between two of them, or it may represent 

 another variety quite as good as some of those listed — which are merely those to which 

 names have been applied. 



The 19 varieties of Crinometra brevijrinna herein recognized fall into four types 

 which when typically developed are quite distinctive, but which intergrade to a greater 

 or lesser extent. These four types, with the included varieties listed roughly according 

 to the increasing specialization of then' distinctive characters, are: 



1. Pulchra type; division series and arm bases smooth, without ornamentation; 

 219-562 meters; temperature 15.33° C. (angusta, pulchra). The varieties angusta and 

 pulchra are probably only alternative forms of the same variety, with the IIBr series 

 either 4(3+4) (angusta) or 2 (pulchra). 



2. Granulosa type; ornamentation of the division series and arm bases consisting 

 of rounded or flattened granules, either confined to the borders of the ossicles or generally 

 distribute'; 185-475 meters; temperature 16.53° C. (granulifera, granulosa). The 

 varieties granulifera and granulosa are probably only alternative forms of the same 

 variety, with the IIBr series either 4(3 + 4) (granulifera) or 2 (granulosa). 



3. Spinosa type; ornamentation of the division series and lower brachials consisting 

 of sharp conical spines or sharp dentations; 139-479 meters; temperature 8.33°-18.20° C. 

 (ornata, coronata, gemmata, spinosa) . The variety spinosa is probably only an alternative 

 form of the variety gemmata with the IIBr series 2 instead of 4(3+4). 



4. Insculpta type; ornamentation of the division series and lower brachials con- 

 sisting of blunt tubercles, knobs, or more or less broad rounded ridges; 159-567 meters; 

 temperature 8.89°-16.67° C. (brevipinna, pourtalesi, diadema, margaritacea, tuberosa, 

 transversa, concinna, pulchella, gracilis, insculpta). This is Hartlaub 's Tuberosa type 

 renamed so as to avoid confusion with Glyptometra tuberosa. 



From the standpoint of the conditions in the other genera in the family Charito- 

 metridae it appears most logical to regard the Pulchra type as the generalized stem 

 type from which the others have been derived, and within the Pulchra type the variety 

 angusta is more generalized than the variety pulchra. 



The Pulchra type passes insensibly into the Granulosa type. 



From the Granulosa type there are two lines of development; the granules may 

 elongate and become pointed, resulting in an ornamentation or more or less stout conical 

 spines or dentations, such as characterize the Spinosa type; or the granules may become 

 enlarged and elongated into blunt tubercles or ridges with rounded crests, such as 

 characterize the Insculpta type. 



In the family Charitometridae the IIBr series, when present, are usually 4(3 + 4), 

 or in the majority of cases 4(3+4). In the Pulchra and Granulosa types IIBr series 

 of 4(3+4) and 2 seem to be equally common. In the Spinosa type one variety, 

 gemmata, has the IIBr series 4(3+4), the other three having the IIBr series 2. In the 

 Insculpta type the IIBr series are in all the varieties 2, though in some a few of them 

 may be 4(3+4). 



The Insculpta type is an interesting parallel to the East Indian genus Glyptometra; 

 while the Spinosa type includes the only spiny forms in the family Charitometridae, 



